Advice on polishing

[bhays]

I got a new larger throttle body for the tuned port setup on my current project today. The rest of the setup is chromed and the new throttle body is a pebble type finish aluminum.

I want to get this one plated to match, and I need to polish it before I send it off. The name plate. What sequence of grits should I use to get to a polished finish?

Thanks for any advice.

 

[ibedayank]

first you sand starting with 120 and work your way down to at least 320 use wetdry and keep it wet or it will clog

 

[zkling]

I'd contact two people.
1-The folks that make the body, and ask how they finish it. It may be annodized. Tell them what you plan on doing.
2-Talk to the plating shop to see if they have any requirements on minimum recommended finish before plating.

Getting that to a high smooth polish is going to take a bit of work to remove the textured surface.

 

[ilovevocs]

If its anodized you can easily tell by rubbing it with some aluminum polish. If it doesn't turn black from removing oxidation its coated and you need to strip it. If anything it may be clear anodized but it doubt it.

Your going to need a buffer or retrofit your bench grinder with buffing wheels. Polishing is dirty, youll get dirty and your shop will get dirty. Honestly if you don't have the materials on hand I would pay to have it polished, their going to be no cost benefit to doing it yourself. If you want to do it still I would be willing to find an online retailer for the compounds and wheels to point you in the right direction. Their are allot of ways to achieve the same result when polishing. Your basically just removing material to flatten the surface. Each step removing less material. I have polished / plated everything from ATV cylinders and frames, to car rear ends. At the time that I was doing allot of polishing I built a relationship with the foremen at a local plating shop that ran bumpers for ford. I gleaned allot insight from this relationship and was able to plate allot of things. The polishing is the bulk of the work but the quality of plating job will make or break the final finish as well.

 

[bhays]

Can anyone give me an idea what the normal charge for polishing an item such as this would be vs me doing it myself and them just plating it? That would be the decision making factor.

 

[ilovevocs]

It's a small part but a PIA part as well. I don't see anyone polishing it for less than $80.00. Most plating shops in my area don't like to mess with small jobs or custom work so they overcharge to make it worth their time. Your going to find the quotes you get from local guys ranges wildly and some won't even talk to you. At least that was my experience. The ones that would talk to me had two month lead times. Once I started polishing my own parts finding someone to plate was simple. For me it wasn't so much cost driven as just general lack of availability of the service. That and I enjoy it, something you can pound a couple beers, crank the radio up and just go to work, not much thinking involved once you get the hang of it.

You should know with as rough, small, and contoured as your part is it's going to take someone with a little skill to polish it without distorting it because your going to remove allot of material to achieve the desired result.


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[GTA Matt]

I have the same throttle body, the rough casting has to be ground smooth, then brought back up to a shine. I polished my old tpi setup and my mini ram the same way. Took off the casting with a roloc disc, then back up by hand using progressively smoother sand paper by hand, then polishing rogue and a buffing wheel on a die grinder, and a final hand polishing. Makes for a good, rainy weekend project.

 

[bhays]

I have these discs on hand, would this work?


Which ones should I start with and then what would the progression be? Then which gris of paper should I work through?

 

[Barlow L]

I use the 3m Convolute Deburring Wheels on a bench grinder to polish out machining marks on aluminum and brass. They are expensive but work very well.

 

[zbadass28]

Go on eBay and do a search for polished TPI. There's a guy on there that will do it. He gets 450.00 to do the top plenium, throttle body, runners, and the lower intake and to powder coat the linkage and brackets for the throttle body. And I think he polishes the water neck to. He may even throw in the aluminum corvette distributer cover to for extra money. Polished as well. Does very nice work.

 

[rodm1]

I use the 3m Convolute Deburring Wheels on a bench grinder to polish out machining marks on aluminum and brass. They are expensive but work very well.

Those would work well to start removing material and some of the finishing as well. If 3m makes them for a die grinder I would give those a try, cartridge roles, and cratex would be an option.

Your roloc disc's will definitely be helpful to. In short you are going to have to try a few things until you find something that works. The finish will be identical to how your part will turn out. Any gouges or irregularity will show up in the finale product.

 

[CudaChick1968]

If you're still inclined to polish that tb yourself, start here ... it's a good primer.

http://www.caswellplating.com/buffman.htm

Caswell has pretty decent prices on compounds, buffs, wheels, etc., too. You'll probably run into links to a company called Eastwood -- if you do, keep looking; everything they sell you can find cheaper somewhere else.