Buffing 101

[SY2932]

PART 1

Okay so you decided that you don't spend *enough* time under the hood of your truck as is and you want to spend even *more* time. First off, I would like to apologize for not being true to my original post on this very subject, "polishing a turd". Even though I eluded to the shortcomings of polishing my intercooler and upper intake, I did like everyone else and posted pics that showed the good:


but not the bad:


and the ugly:


The bottom line is these parts were NEVER meant to be polished. The impurities that are inherent in ALL the intakes that I have personally seen both polished and unpolished, coupled with the rough casting makes them undesirable to do so. On my intercooler, there are spots that are now so thin, I can push on them with my finger and it feels like the bottom of a soda can... I already mentioned that I hand sanded through two spots and had to get it welded . The techniques in this write up were not "modified" in anyway now that I "know better" from doing my own parts. My approach from the get go was to "remove as little material as possible to achieve a satisfactory finish" based on the experiences of others who have done this before me. This is not meant to scare anyone off, I'm just trying to "keep it real" so anyone who decides that they really want to do this knows what they are getting themselves into...

This write up will consist of two parts, part one is polishing i.e., sanding away the rough casting marks to make and smooth surface so that we can buff it to a mirror like finish. BTW even though polishing and buffing are used interchangeably, they are not the same. Polishing means sanding to smooth surface and buffing means giving the surface a mirror like finish. Anywho, before we can start we are going to need some tools and equipment:


For you folks out there who don't own a decent air compressor, this is a great time to invest in one. A corded sander isn't going to cut it on an intake simply because there aren't very many flat spots on it. I get most for my polishing supplies from the gentleman that sells to where I work, Dave Glenn of Artco (American Rotary Tools Company). His number is 586-909-2231. Usually, they have a minimum order requirement but I spoke to him about it the last time he stopped by. He said that they would overlook that since you guys prolly won't want to buy several hundred or a thousand or so dollars worth of polishing supplies/equipment at one time...

The 2" 3M Grinding/Sanding/Finishing Kit can be had at Autozone of Walmart for under $20 and you will be able to get quite a bit done with this alone. It is important to note that this is a twist lock type system whereas the disc is threaded in the center. I have the "hook and loop" style as well but I don't care for them as it is difficult to get the disc dead center and when you are spinning it at several thousand rpms, your finish will suffer as a result of the disc being off center.

I got the braided air line from Artco and I couldn't work without it. When you are working with a tool for hours on end, you want to comfortable using it. The braided line weighs nothing and you forget that you are even connected to the air compressor. I have an inline pressure regulator that I bought from Harbor Freight on the end where it attaches to the shop air. Makes it so that I can run the grinder "full throttle" by simply adjusting the line pressure. That way, I don't have the "feather" the throttle to get the right rpm that I want.

Undoubtly the biggest aid in sanding has been discovering grinder's grease a few years ago (that is it to the left of the 3M kit in the pic above). That can be had from the Eastwood Company. I prevents the sanding discs and cartridge rolls from loading up when sanding aluminum. It makes a HUGE difference. A little goes a long way, my tube is over three years old and I haven't even used a third of it yet.

Now for a word on safety. You will DEFINATELY need a dust mask especially when you start sanding. It makes a HUGE mess. I also wear an apron if that tells you anything... Depending on how loud your grinder is and your proximity to the air compressor you will want ear protection too. I do the bulk of my polishing and buffing at work since it has a huge air compressor that is housed in another building so I never even hear it running. I have a Craftsman 6HP 33 gallon at home that never stops running and I have to stop after about ten minutes to let it "recover". The safety glasses are a no brainer since sanding and high rpm's are involved.


Ok on with the show . The owner of the donor intake had painted the emblem so the first thing that I did was tape it off so that I could bead blast it out. The tape is to prevent pitting the aluminum surrounding the emblem. Even with VERY low pressure, it will still pit the material. For this reason, I would not recommend blasting to remove the coating that is on it. You will be VERY sorry if you do...


Here, you can see a mount that I made to hold the intake when I am working on the top. Due to it's shape, it isn't very stable when resting on it's base. Which brings me to an important point. The upper intake is a cast part and it should go without saying but, be VERY careful handling it. If you accidentally drop it, it will SHATTER like a clay pot! The mount works great when you are dressing the area that the emblem is on as you will see later. It is simply a 2X4 with a piece of plastic between it and the intake protect the sealing surface from getting dinged up while I'm working on it.


This is the aftermath of a 50 grit sanding disc. If you have never power sanded anything before, it is very important to KEEP THE TOOL MOVING AT ALL TIMES! If you don't, you will put a decent sized gouge in your part VERY quickly! At this point you are probably asking yourself what did you get yourself into... You can see that I have a towel under the intake since I am working on top of a steel bench. Anytime sanding is going on, the grinder's grease is close by. At this point I move on to the next grit. You may ask why when there are still patches that didn't get sanded clearly visable. Remember my goal: "remove as little material as possible to achieve a satisfactory finish". The reason is, you will remove MORE material as you progress through the various grits sanding. Ideally when you get to your final grit, there should be very few spots that you will have to address since you will have sanded to the level they were at. This is something that only experience can teach. Fortunately for the most part, the upper intake has plenty of meat to it. Therefore, the chances of you sanding a hole in it if you get over zealous are minimized.

Time for some more tools and equipment:

A long reach die grinder with a selection of cartridge rolls in various grits to get into those places that the sanding disc's couldn't. Grits are 80, 120, 240 and 320.


Cleaning up the valley here. Note that the intake has been sanded with an 80 grit followed by a 120 grit sanding disc at this point.


Just to show that there is still more than one way to skin a cat, here is the results of bypassing all the sanding discs entirely and going straight to a 3M Scotch-Brite disc. These are the last item that I use powered on the flat surfaces before going to block sanding. This can save you some time and doesn't make *quite* as big of a mess and you don't even need grinder's grease to use them. I prefer to use the sanding discs because it is easier for me to see where it is cutting at.


Obviously, this is the most time consuming part on the intake. You are going to need even smaller tools to clean up that mess:


Dremel 395 varible speed rotary tool with a flexshaft attachment to get into the *really* tight spots. As well as a selection of ceramic "Super Stones" to sand places no rotary tool can get. If you are on a buget, you could press a Dremel style tool into service where the long reach die grinder was used previously.

 

[SY2932]

Re: Buffing 101


Cleaning up some tight spots with *very* small cartridge rolls. I have these in 80, 120, 240 and 320 grits. I got these as well as the mandrels for them from Artco. The part number on the rolls is preceeded by the suffix "CR04G" then the grit number. These rolls shape material VERY fast due to the small area of the roll that is in contact with the work. The mandrels are 1/8th shank size part number PM01, PM03 and PM04. Some of these mandrels are used for the larger rolls. The larger rolls are in the same grit and have the suffix "B2 RB" followed by the grit number. When cleaning up areas like this, the immediate desire it to just run the roll right up against where the two faces come together and go to town. You CAN do that but you will end up with a gouge in the surface all the way around it... IMHO, that is amateurish at best and shows a desire just to get the job done. Rolling across the two faces before diving into the corner will prevent this.


Ok so you may or may not have noticed that the Dremel is not being used in the pic above. Fortunately, I have the freedom to use any tool that I wish where I work so, it's hard to turn down a NSK Rotus III. Foot pedal operated, quick change collet, variable speed on the handpiece and reverse makes it hard to turn down. Artco sells these as well and at over 1K in price, I won't own one anytime soon...


Moving *slowly* along. This is after roughly 16 hours of sanding.


Time for some emblem dress up. I have always HATED how crooked the ends of the raised area the that emblem is on are. It is worse on some trucks than others. All this work is being done with the intake clamped in the vise. Before.


And after.


On this intake, the opposite side of the plateau is very shallow. Here the ceramic super stone is being used to clean up what is left of the casting as well as establish the rounded contour. Artco sells the ceramic super stones and they come in several sizes. I found that the 4mm and 6mm in 120 and 300 grit gets just about anything done. The only thing that I found them lacking for was polishing the steel in my TB bracket. Dave hooked me up with some diamond stones and life is good again. The part number on the stones is suffix "SE10" followed by the size in mm for the 120 grit. Suffix "SL10" followed by the size in mm is for the 300 grit. The Holders are sold seperately and the suffix for them is "SSH0" followed by the size in mm.


Here is a 3/4" sanding disc in use. This is nice for the flat areas that the bigger 2" is too big for.


I know my work gets these from Dave as well but, I don't know the part number. These aren't a "must have" item but, they are nice.


Here you can see that I have block sanded the area that was went over with the sanding disc to reveal any high spots. Looks pretty flat so I did a good job which isn't easy with those small discs...

Yup, I just said the "B" word. Ok, now is time to choose what camp that you want to be in. If you don't care how your part comes out only that it's SHINY and looks good from 10 feet, you can disregard probably the next page or so because it's not for you. Block sanding is for the individual who wants the highest finish possible free of distortion. And the only way you can achieve that is a PERFECTLY FLAT SURFACE. Ever see a *really* bad chrome job where the metal that was plated wasn't smoothed before the chrome was applied? Yeah, it's shiny but that's all it's got going for it... When it's all said and done, you will probably spend about a quarter of the time buffing (probably less) that you spent doing all this sanding. In that regard it's not so different from painting. We all want to see the payoff for all this work, stick with it and you won't be disappointed.


Didn't do so good here though . All those bright spots are high spots and must be sanded down to be level with the rest of the surface if we desire a ripple free mirror finish.


This is the stuff that will try your patience. There is a low spot here that I wish to eliminate.


And thirty minutes later using a 150 grit sanding block...

***That concludes this installment, more to come soon***

 

[SY2932]

Re: Buffing 101


You could call this a "poor man's polishing kit" since it really has everything that you would need to get the job done. However, it would take almost as long as it is taking me to complete this write up... These are the last "tools" that I use prior to pressing the buffing wheels into service. When block sanding, WD-40 works GREAT for keeping the sandpaper from loading up. It acts as a lubricant in the same way that the grinder's grease does. Use a paper towel to wipe if off to observe your progress.


This is my favorite sanding block due to it's versatility. You can use it like a long thin block or just the tip like a pencil eraser. I am going to make a custom one out of 6061 aluminum soon since the surface is starting to get rough from peeling off the sandpaper. Incidentally, the sandpaper that I am using in made by 3M and it has an adhesive backing on it so you can stick it on just about anything. The grits I work with are 150, 220, 320 and 400.


Another sanding block. This one is good for sanding the flats where the bolts go through due to it's thin profile. The edge is good for sanding the sides of the bosses on the vacuum fittings and where the throttle body cable bracket mounts.


Areas like these will try your patience. Unfortunately the way the casting process works guarantees that you will encounter spots like these where there are several faces coming together in close proximity to each other.

 

[SY2932]

Re: Buffing 101


It's bound to happen sooner or later, you will encounter an imperfection in the surface and you will have to decide if you can live with it or not. Hard to see in the pic but this one went pretty deep. Therefore, I opted to let it go. Fortunately you can estimate how "material safe" you are when sanding the intake. All you have to do is pinch the area between your fingers from the inside and outside. When working on an intercooler, you don't have this luxury. That's why it is so easy to sand a hole in it. Of course this trick won't work on the throttle body side where the EGR passages are at.


This imperfection (looks like a chili pepper) is on the front of the intake and will be in plain view. As a result, I will try to eliminate it. Notice how there aren't any other imperfections on the surface other than the few that I still need to address around where the throttle body bracket mounts to.


Hitting it with a 150 grit sanding block and WD-40.


Wouldn't you know it, I *just* sand down to the top of the imperfection and look that appears :roll: . When you encounter these voids remember that they are essentially "bubbles" in the aluminum. What starts out as a small pit will get bigger as you keep sanding it away because you are basically cross sectioning an "O". Eventually, it will go the other way and the pit will get smaller. The problem is when you have a lot of them and they aren't all at the same level. I had to cry "uncle" on this imperfection because the more I sanded, the more voids I exposed.


Speaking of items regarding the casting process, you may or may not have noticed that there is a "seam" on the front of the intake as well as the back. You can see where the two halves came together from the inside during the casting process. The one on the front runs right down the middle of the bosses for the throttle body bracket. The rear one goes straight down from the "flat" on the side of boss for the vacuum fitting. I sand these seams flat. The front one isn't too bad but the rear one is like the bow on a ship.


If the sound of finger nails on a chalk board makes your hair stand on end, you aren't going to enjoy doing this. Here, I am cleaning up the casting identification using super stones. Using WD-40 as a lubricant will quiet down the screeching a *little*... Later I will use small burrs to clean out the insides of the characters that I can't get with the super stones. Block sanding the tops of the characters really makes them stand out. This IS a tedious task and only the most anal retentive folks will be willing to do this.

The choice to retain these marks is up to you. Just remember that if you decide to sand them off, there is no going back... My feelings are that there aren't very many items on the truck that document the collaboration between GM and PAS that made these trucks possible. This particular casking mark is high profile and you can't miss it. It's not going to fall off or fade like a sticker in a door jamb may. Even though the owner told me that I could sand it off, I don't like to deface anything that speaks of the history of something. If I was going to remove a major casting identifier such as this, I would remove ALL identifying marks since I would be going for a perfectly smooth look (that's right, no "syclone 4.3 turbo"). But that's my :2cents: .




Slowly but surely getting there...

 

[SY2932]

Re: Buffing 101


You need small tools for small jobs. These are for cleaning up the casting identification where even the super stones can't reach. The ball burr has a diameter of .046" and the drill is a #66 which is .033" diameter.


If you eyes aren't what they used to be, a magnifying lamp like this one will help you see what you are doing. The burr is to get inside letters and numbers.


The drill is to get into spaces to small even for the burr like the opening in the "A" and down inside the "snowflake".


A small piece of sandpaper folded in half works good for blending in the areas between the characters that were cleaned up with the super stones.

 

[SY2932]

Re: Buffing 101

I thought about covering this portion in a separate thread altogether since it really has nothing to do with finishing. However, it may be beneficial to keep the two topics together since they both require having the upper intake removed from the truck. It may also prevent members for having to search for it if they wish to do this while the upper intake is removed to be finished. Either way, I have made this a separate post so that the powers that be can easily move it if they see fit...


If you have deleted your EGR, this is something you may want to consider. Even with a block off plate, exhaust gas is still flowing up one side of the intake heating it up. Tapping the bottom of the intake where the exhaust gas enters and installing a plug will prevent it from ever getting in there in the first place. This will require a 3/8 X 18 NPT tap and plug. The tapered reamer is to ream to hole so that the tap can start true in the hole.

When using pipe taps, DO NOT turn the tap down until it bottoms out. Cut several threads, back the tap out and test fit the plug until it screws in *just* below flush. Afterwards take a small roll pin punch and stake (crush) the threads in two or three places so the the plug CAN'T BACK OUT. However, DO NOT STAKE THE PLUG UNTIL THE INTAKE IS COMPLETED! The reason is you will want to be able to clean the EGR passage with air, brake cleaner, carb cleaner, etc. to remove ALL traces of grit from the sandpaper and buffing compounds before reinstalling it on your truck. This is important because any grit left in there WILL find it's way into the motor if you don't...

I use brass plugs with ultra high temperature anti seize (good to 2,000 degrees) in the event I decide return my truck to stock (not very likely). Using a plug constructed of any other material will effectively weld itself to the aluminum and you will never get it out.


I was very surprised to see that this owner hadn't taken the time to gasket match the upper intake. You can see that there is a good 1/4" of material that can be removed from each of the ports. After dropping a few 5/16" bolts in a few of the holes to hold the gasket in place, I scribed where material needed to be removed. The scribe marks were them traced with a marker to make them easier to see.


If you ever need to hog away aluminum, this is the right tool for the job hands down. A solid carbide burr. Carbide is extremely hard and equally as brittle. Drop one of these on the floor and it will shatter. These cut aluminum like a "hot knife through butter". Use a little grinder's grease and watch the chips fly... Just be careful to not go "hog wild" and cut a hole right through the wall. A "middle of the road" rpm works best with these. Too much rpm and it will skip across the part rather than cutting it. This is an 1/8" one I am using here and it is much easier to control than the 1/4" that I used several years ago when I did this mod to my truck.

When using these burrs, you need to take eye protection SERIOUSLY. The chips these produce are like the ends of fish hooks. And there are a lot of them... Anytime an aggressive cutting tool is being used on a gasket sealing surface, you must *control* the tool or else you could end up with a nasty gouge if you're not careful. Try to take too heavy of a cut and the burr WILL grab the work.


All hogged out.


Putting a radius in the corners.


Block sanding the port tangent to the scribed line and rolling it to give a smooth transition.


This just goes to show that the imperfections that you have to deal with on the outside exist on the inside as well :roll:...


Completed.

 

[SY2932]

Re: Buffing 101

With all the casting marks having been addressed in the nooks and crannies it's time to do some hand sanding. Believe it or not, there won't be anymore sanding after this and you will *finally* get to see some results. In the sandpaper, I progress through the grits starting at 150, 220, 320 and then finishing with 400 grit. The contours on all the rounded edges should have been finished with a 320 grit cartridge roll so, you should really only have to sand them with the 400 grit sandpaper and they will be done.

When handsanding, you will get a "feel" for the resistance that is required to sand the part with each of the various grits. The coarser ones will tend to "grab" or "bite" more than the finer ones will. If at any point when using the finer grits you feel unusual resistance or hear a scratching noise, STOP WHAT YOU ARE DOING! Usually the cause is something that has gotten onto the paper that doesn't belong there like dirt or some other foreign matter. This will put DEEP scratches into the surface and you will have to start over again to get them out. Because of this, I always wipe off the area where I am working at and flick the sandpaper to make sure that it is clean.

Also, don't finishing sanding with a new piece of sandpaper before moving onto the next grit. A new piece of sandpaper will cut much more aggressively than an old piece will because the abrasive will be sharper. Doing this will result in scratches that will take much longer to remove when you move onto the next grit.

On a flat surface, the proper way to sand it is to sand perpendicular to the previous grit. The reason for this is so that you can see when all the scratches from the previous grit are completely removed. Works great for large flat surfaces but it isn't practical when doing small areas or the tops of rounded areas like the EGR passages. In spots such as these, you will have to sand it until you *think* that you have removed the scratches left by the previous grit. I say *think* because it's very easy to get in a hurry at this stage and move onto the next grit too soon.

The easiest way to see if any scratches remain this is to clean the surface after you sand it. Simply wiping the area off won't work because the fine dust produced from sanding will conceal the scratches left by the previous grit. I use lacquer thinner to clean the metal. It also works good for cleaning off the buffing compounds later as well. This will allow you to see what the true surface condition looks like. This usually exposes a few more voids in the surface that you didn't see before too :roll: ...


By the time that you are finished, there should be a nice brushed look to the part. It should have a dull shine to it. A few minutes with a sprial sewn buffing wheel and tripoli compound is all that's needed to get the shine to "pop" out. Which (finally) brings us to part 2:

 

[SY2932]

Re: Buffing 101

PART 2


These are the tools that will bring this project to a close. A decent sized grinder/buffing motor, ventilated flap buffing wheel, sprial sewn buffing wheels, a loose section wheel, felt bobs, tripoli and white rouge compounds, a rake for cleaning the buffing wheels, a die grinder, cotton gloves, safety glasses and most importantly a mask.

I haven't broke down and bought a "legit" buffer yet but, it's on the horizon... I have been using my 8" grinder for several years now with excellent results. For buffing metal, you need to have over 3,000 RPM on tap. Anything lower, and you won't have enough surface speed to get the best results (when working with plastic, 1800 RPM is the way to go BTW). The advantage of using a "true" buffing motor is that the buffing wheels are mounted further away from the housing than they can be when using a grinder. This allows you will buff the around the part without hitting it against the motor housing. The longer shafts on buffing motors also allow you to use more than one wheel (two side by side on the same shaft "stacking" the buffs). However, turning more than one wheel under load takes a considerable amount of HP. Such a buffing motor costs several hundred dollars. Not something for a casual user by any means. My grinder is rated at 3/4 HP peak and it has no problems turning 6" buffing wheels. The "C" clamps are to clamp the grinder to any bench since I have it mounted to a 2 X 8 to make it portable.


Before you can put a grinder into buffing service, you may have to *fabricate* some parts. Usually, a decent sized grinder will have grinding wheels with a 5/8" diameter hole in them which many be too small for the wheel that you are using. The mounting hole size on buffing wheels varies from manufacturer to manufacturer. You can see that I made a plastic sleeve to keep this wheel centered on the shaft. The two short sleeves are spacers to hold the mounting washers away from the motor so that the wheel can be pinched between them.

Buffing wheels come in several styles. For finishing aluminum, I use ventilated flap, sprial sewn and loose section wheels. The ventilated flap and sprial sewn is used for "cutting" with tripoli compound. They will remove minor scratches in the surface provided that they are not deep ones. A loose section wheel is more for "coloring" than cutting although it does provide a slight cutting action when used with white rouge compound.

When working with buffing wheels, always mark the direction of rotation and the type of compound used on the wheel. And NEVER use different compounds on the same wheel. This is to prevent cross contamination on your wheels. This rule holds true for felt bobs as well except the rotation part since you can only mount them up one way... I keep all my wheels by compound type in ziploc plastic bags to keep them clean and organized.

The rake is used to remove caked compound from the wheels while they are rotating. Obviously, you need to be VERY cautious when performing this operation. But the same is true for ANYTHING involving a buffing wheel. ALWAYS buff off an edge and NEVER into one. If the wheel catches the edge of the part, It will be thrown with CONSIDERABLE FORCE! This is hard on the part and you if you happen to be in the way when it happens...

A pair of cotton gloves will help keep your hands clean and prevent burns if you touch an area that was just buffed. Buffing metal produces A LOT of heat FAST! When working with thin parts you have to be careful not to warp them which isn't a problem on an intake. Buffing is a dusty operation and you will inhale a lot of aluminum/compound dust if you aren't wearing a mask. Make sure that you have a pair of safety glass on hand too.

 

[SY2932]

Re: Buffing 101

After you mount up a new buffing wheel, you should run it for at least a minute to spin out all the loose fibers. After that, I rake it a little to help put out any fibers that weren't spun out. Loose section wheels will shed the most strings due to their construction. And it's not unsual for it to "rain string" for a few seconds after you spin it up the first time.

To start off, I use a ventilated flap buffing wheel since it cuts twice as fast as a sprial sewn one. This particular wheel is a treated wheel and it cuts more aggressively than a nontreated one. I purchase all my buffing supplies from Eastwood. The compounds are what actually do most of the work when you are buffing. The buffing wheel is just a carrier for the compounds. The compounds are applied to the wheel while it is rotating. The compounds resemble a hard wax and the heat of the buffing wheel melts it onto the wheel. You don't need a lot, a little compound goes a long way. Touch it lightly against the wheel for about a second and that's all it takes.

If you start seeing BIG black clumps of compound on your part, STOP! You have too much compound on the wheel. Rake it and that will clean the wheel up. Don't try to "wear off" the excess on your part or else you will end up with little grooves where the compound is clumped. The reason is when the wheel comes in contact with this clumped up compound, it will CUT INTO THE PART immediately behind it. You will want to wipe off these clumps before you proceed. Lacquer thinner works great for this and it is inexpensive. For this reason, I use it to clean off all the residual compound before moving on to the next one. This is to prevent cross contamination on the wheels.

When using ventilated flap and sprial sewn buffing wheels with tripoli compound you will be using "cutting" strokes. That is, moving the part AGAINST the direction of the wheel rotation. The reason is this action "pushes" the tripoli compound in front of the wheel and keeps it there, so that it can smooth out the surface.


When buffing, everything happens BELOW the center of the wheel. If you bring the part up too high, it will start "skipping" off the wheel. You can clearly see here how a grinder motor limits what you can do... See how close the intake comes to the motor housing?

A few years ago, I hooked up a friend with a similar grinder/buffer set up with 8" wheels (larger grinder). I tried to use one of the larger 8" wheels on mine but, it didn't have enough HP to spin it under load . The grinder he got was 1 1/2 HP. So, don't tell me to just use a bigger wheel to get more clearance ...


Once you start putting the wheel to work, more threads will work their way out. Some will need to be trimmed.


This is the result after five minutes of buffing with the treated ventilated flap and tripoli compound. The reflectivity will increase with continued buffing as more scratches are eliminated from the surface.


When getting into tight spots, think about how you are going to do it first BEFORE you do it. If you have to, turn the buffer off and see if you will be able to make it without catching on anything.


You will really need to pay attention to what you are doing when buffing areas like this. It is VERY EASY to roll off a rounded edge when buffing. In this case going off to the left means catching that sharp corner. Anytime you buff into an edge, it can get ugly QUICK. Always remember that wheel is spinning at over 3,000 RPM...


Don't buff anything that has sharp edges or fine detail with an aggressive wheel and compound or else you will round off the edge(s) and wash out the detail. For that reason, the ventilated flap isn't used on the emblem or any of the casting identifiers.

For the emblem, I use a regular sprial sewn buffing wheel that is mounted on the other shaft. I like to use two wheels with the tripoli so that I can tailor how aggressive the cutting action will be. Ventilated flap for the heavy cuts, sprial sewn for the light ones. One area of caution is the emblem, very light pressure is needed here or else you will "pull" the letters.


This shows the start of what happens when you do it the wrong way. This is going to sound like deja vu... See how the sharp edges in the emblem scraped off the tripoli compound and it got built up? Once that happens, everytime you run the wheel over that spot, the tripoli compound does what's it's meant to do, it cuts the surface. And because there is a decent sized deposit there, it cuts A LOT. If you continue to buff a part like this, there will be furrows in the part immediately behind the letters/numbers in the direction that the wheel was rotating. Remember, buff OFF edges, not INTO them.

 

[turbodig]

Re: Buffing 101

I was very surprised to see that this owner hadn't taken the time to gasket match the upper intake. You can see that there is a good 1/4" of material that can be removed from each of the ports. After dropping a few 5/16" bolts in a few of the holes to hold the gasket in place, I scribed where material needed to be removed. The scribe marks were them traced with a marker to make them easier to see.

When using these burrs, you need to take eye protection SERIOUSLY. The chips these produce are like the ends of fish hooks. And there are a lot of them... Anytime an aggressive cutting tool is being used on a gasket sealing surface, you must *control* the tool or else you could end up with a nasty gouge if you're not careful. Try to take too heavy of a cut and the burr WILL grab the work.


All hogged out.

Not to hijack your thread (it's a keeper!), but there's a reason to *not* do this.

If you were to look down inside the upper intake, you'll see that there is an incredibly tight radius on the short side of the manifold. Your matching just made it a lot tighter.

Instead of hugging the radius of that turn, air will now "ski jump" off it, and will effectively limit the size of the port inlet.

If you mate the stock upper and lower as they are cast, and look through the lower up towards the upper, you'll notice the fact that despite the mismatch at the surface, the overall radius of the turn is pretty good. The "notch" in it, caused by the mismatch, actually serves as a bit of an anti-reversion dam.

If you really want to fix the issue, the upper intake needs to be built up just above the flange, such that you can create a more sweeping turn on the short side. The long side needs to also get radiused to blend into the lower.

The lower itself doesn't take much work, outside of the injector humps. Obvious casting bumps should be taken out, but overall the shape is ok.

Not trying to rain on your parade, just wanted to bring up the issue with the radius of the turn.

Later,

 

[SY2932]

Re: Buffing 101

Thanks for the heads up, "you live, you learn, ya love" . I have never been crazy about the sharp radius that exists in the upper intake "unmodified". Gasket matching only makes it more so. It's interesting that you mentioned this because I was thinking about this just the other day. I was considering hogging it out even more to streamline it better since there is plently of wall thickness in the corners. I have seen some pics before where the transition was REALLY hogged out along with the other three sides as well. However, even that sounds like a moot point...

Well, that does it! No more carbon copies of that "Brian Green" guy's truck ...

 

[SY2932]

Re: Buffing 101

The following is a series of pics showing how I position the intake to buff it. Notice how I have my fingers inside the intake if I can do so in the event the wheel grabs the part:










This is the direction that I should have buffed this area in the previous post so that I wouldn't be buffing into a corner... That pic in the other post was to draw attention to possible "trouble spots" if you aren't careful.


You probably won't want to try this until you have spent at least a *few* hours in front of a buffer...


Using the sprial sewn wheel around the casting identifcation,


and base as to not round off the corners.

 

[SY2932]

Re: Buffing 101


Felt bob is in use here with tripoli compound. Felt cuts very FAST. If there are any scratches left from when I was sanding. they get hit with this. Now that I am getting pretty involved with metal finishing, I will probably buy a felt wheel for my buffer sometime in the near future. These are what you use to get into the tight spots. You can shape the bobs by running them up against a sharp corner like the edge of a flat bladed screwdriver.


For all the tight areas, you will need smaller wheels and bobs. And Dremel offers a great assortment for little cash.


I think Dremel made this wheel specifically for syty intakes...


You can really go to town with these small wheels and bobs. They work great for buffing around the emblem without fear of pulling the letters due to their small size. However, use a little discretion and don't forget that there is a screw on the end holding the sprial sewn buffing wheel on. The other felt wheels and bobs get screwed onto a mandrel. Get to close to a wall or angle it to much the wrong way and you are going to have to get the sandpaper back out after that screw scratches up your freshly buffed intake...

 

[SY2932]

Re: Buffing 101

After hitting the bulk of the intake, it gets wiped down with lacquer thinner to remove all the tripoli compound. At this stage in the game, anytime that you wipe the intake be sure to use a 100% cotton rag. I use cut up old t-shirts for this purpose. If you use a paper towel, it WILL scratch the intake! This is what it looks like after about four hours of buffing:


From there, the white rouge and loose section wheel get pressed into service. When using white rouge, you do a "coloring" stroke which is the opposite of a "cutting" one. When cutting, you go AGAINST the direction of the wheel to keep the tripoli in front of the wheel so that it can keep cutting. On a coloring stroke, you go the SAME direction as wheel rotation because you are laying down the white rouge to give the part luster. One thing to keep in mind with a loose section wheel and white rouge is that you have to hold it against the wheel longer to load the wheel up. The reason is the loose section wheel isn't as stiff as the ventilated flap or sprial sewn so it doesn't generate as much heat to melt the compound. The easiest way to load the wheel is to just hold the compound against the wheel until it starts to melt...

The white rouge and the loose section will remove the minor scratches left from the sprial sewn and tripoli compound. White rouge cuts but, it is VERY slight. So, if you have any serious surface scratches, white rouge and the loose section aren't going to remove them. I didn't take any pics of the this step because they would just be carbon copies of everything that I did with the tripoli compound.


I have just buffed this area with white rouge.


A little metal polish to brighten it up some more.


The $ shot.

 

[SY2932]

Re: Buffing 101

In closing, I can't over emphasize the importance of THROUGHLY CLEANING the inside of the intake! Pay particular attention to the EGR passages (if you threaded the passage for a brass plug, stake it in place after you are finished cleaning). Compressed air works good for getting all the grit out. Carb cleaner works good for cleaning all the grime that has collected up on the inside. Spray it down good and let it pool in the bottom with the intake upside down and let it sit.

I used two cans of carb cleaner on the inside of this intake *before* I started bcause it was so filthy. That's why it looks so clean in pic showing where the two halves on the intake come together from the inside. Prior to cleaning it, everytime I handled this intake, it got me black as a coal stove...

Removing the buffing compound that collects inside the letters in the emblem can be troublesome. Lacquer thinner, cotton swabs and a soft bristled toothbrush will get most of it out. If it is really packed, toothpicks are good for scraping it out. Brake cleaner works good also. For the stubborn compound that seems "welded" to the letters in the corners, HOT soapy water and a soft bristled toothbrush are the ticket. When I say hot, I mean hotter than it comes out of the tap... I took and old soup can (didn't want to use any cookware for this) and set it on a hot plate outside to get it boiling. I used Dawn dish soap and it did a good job cutting the compound. Depending on how much scrubbing that you have to do, you may want to have *several* toothbrushes on hand for this. The one that I used started to melt after a few minutes...

The owner of this intake desired a brushed satin look. After buffing a good portion of the intake for this write up, that was still the finish that was desired. So the 3M Scotch Bright #7447 red pads are pressed into service:


Less than 5 mintues later:

A buffed finish comes off MUCH easier than it goes on...

After taking a few measurements and writing a short program, a new EGR block off plate gets cut on the mill:

And that brings this "project" to a close.

 

[QUICK STORM]

Re: Buffing 101

who is taking all those pics while your buffing?

 

[SY2932]

Re: Buffing 101

who is taking all those pics while your buffing?

My tripod. You can see the legs in a few of the pics. I decided to use it after I almost dropped the intake trying to hold it and the camera at the same time ...

 

[TYRODD]

Re: Buffing 101

Have you thought about selling some EGR plates like that Mike? Mine is too thin and I developed an exhaust/vacuum leak at nats :roll: . Need something that looks gooder than mine too .

 

[QUICK STORM]

Re: Buffing 101

i got my egr block off from RPM, great quality.

 

[SY2932]

Re: Buffing 101

Have you thought about selling some EGR plates like that Mike? Mine is too thin and I developed an exhaust/vacuum leak at nats :roll: . Need something that looks gooder than mine too .

Nah. There are plenty of folks selling these out there and I don't want to "step on any toes". Most folks are happy with a plate that looks like it was made for something else anyways :lol:! Besides, my policy is I won't fabricate something for someone who asks. If I offer however, then that's different...