carguy123
carguy123 Dork
11/5/09 6:56 p.m.

I just bought a set of rims to use on the track. While they don't have to be purty, I don't want to be embarrassed either.

3 of the rims came with flaking peeling black paint on them and one had been bead blasted back to a matte finish. I simply thought I'd blast the other 3.

Now here's the question. The original owner blasted the inside of the hub and the bead area. I thought that was a no-no.

To give the wheels some class, how hard is it to polish out the bead finish? I don't mean high gloss or anything, but the bead finish attracts dirt, fingerprints, you name it. I already know that paint won't stick, or at least I need some sort of base coat for it to stick.

porksboy
porksboy Dork
11/5/09 7:34 p.m.

Are they aluminium or steel? Maching an existing finish will be a biotch. I guarantee your blasting medium will be either coarser or finer than his, also line pressure and technique affect it.

I blasted a set of steelies including the bead seat with out and problems.

I think you want to use glass beads to avoid corrosion issues on Aluminium.

JetMech
JetMech Reader
11/5/09 9:57 p.m.

I just went by Eastwood's site, and they offer things such as walnut shells and soda. The latter might work very well for you if the wheels aren't corroded and you can afford the gear needed for soda blasting.

DILYSI Dave
DILYSI Dave SuperDork
11/5/09 10:49 p.m.

Paint sticks GREAT to a bead blast finish.

blaze86vic
blaze86vic Reader
11/6/09 12:43 a.m.

I bead blasted quite a few aluminum wheels (with some mighty course grit too) and they never had any problems sealing. As long as you don't sit in one area and make a low spot, I don't think it's going to hurt anything. You could always go over the seating part of the rim with some sand paper to smooth it out if you are worried about it.

914Driver
914Driver SuperDork
11/6/09 8:39 a.m.

Use an Eastwood product called Adhereto as a primer. It's a great primer for aluminum.

Dan

Mike Honcho
Mike Honcho SuperDork
11/6/09 8:49 a.m.

I always suggest multi stage finish removal.

chemically remove the paint

shot blast the wheel

walnut or glass bead after that

Paint to taste

It will leave a nice finish and remove the chance of oxidization.

carguy123
carguy123 Dork
11/6/09 9:22 a.m.

The wheels are aluminum.

It's nice to hear paint will now adhere since that's the easiest way to make them look decent again.

It's the bead setting well that had me worried the most. I swear I'd read an article that warned in big bold letters not to blast the hub and bead setting area, but if some of you have done it with no ill effects then I must have Alzheimers.

minimac
minimac Dork
11/6/09 9:45 a.m.

If you're really concerned about the seating area, a trick we picked up years ago was to smear the seating area with grease. Never had a rim leak since doing that.

wayslow
wayslow New Reader
11/6/09 10:17 a.m.

There's actual bead sealer available as well. It's sold in a small can with a brush attached to the lid like contact cement.

I've sandblasted a few sets of aluminum rims and never had a problem.

Mike Honcho
Mike Honcho SuperDork
11/6/09 11:25 a.m.

** This is an area that I am exceptionally well trained in.

If there is oxidization on the tire mounting surface follow these steps:

1: Soak mounting flange with PBBlastr for approximately 1/2 hour, reapplying frequently.

2: Using a green Roloc bristle disc on an angle grinder "grind" the oxidized contamination off the wheel surface.

3: Spray another coating of PBBlastr, wipe off with shop rag.

4: Mix a small bucket of dish detergent and water, clean off wheel.

5: Clear coat or bead seal the resurfaced area.

6: Install tire.

mkiisupra
mkiisupra New Reader
11/6/09 12:25 p.m.

Bead blast the rest to start at the same point with all four wheels.

Like others have said, the bead blast will seal, though you may need a sealant (I never have 3 sets of blasted wheels in my history)

Also, do put a primer or metal prep down before final coats to promote adhesion. In fact, I used 'Bulldog' adhesion promoter in a rattle can on my last set of wheels.

I have used bare metal primers (all in rattle cans) and topcoats from same and different manufacturers, with little differerence between them.

Polishing bead blast to mirror surface is a recipie for early arthritis, this I also know first hand (pun intended.) I took my set of rims on a camping trip to work on my polish whilst chasing bears away from Yosemite campgrounds. Fun times!

Eric G

jpod999
jpod999 Reader
11/6/09 1:32 p.m.

You should be fine with bead blasted machined parts. As long as it wasn't sand blasted, it won't have effected anything, the bead blasting isn't harsh enough to do damage.

I worked at a powdercoating shop over the summer and we bead blasted machined surfaces but never sand blasted them, sand blasting is much harsher.

motomoron
motomoron Reader
11/6/09 4:15 p.m.

Bead blast w/ glass media is fine. It'll seal perfectly. Every tire guy I've ever seen uses bead lubricant and tires happen to be made of rubber which coincidentally makes a fine gasket.

(as an aside, I mount most of my own motorcycle tires and used to do all my kart tires. A kart racer offered the tip that the worlds best lubricant for difficult-to-bead tires is KY jelly. I sort of like having the large economy sized tube in the top of my tool box. "What's ~that~ for" (picking up huge lead hammer and said tube) "people who (don't pay, don't return borrowed tools, etc))

Sand blasting is another matter. It's pretty brutal and removes meterial aggressively enough that you could easily render a bead seat unusable.

I suggest lathering them with aircraft stripper, put 'em in trash bags to keep the volatiles in, let 'em sit. Then pressure wash (safety glasses please) - dry - bead blast.

They'll look fabulous 'til they get all caked with nasty corrosive brake dust compounded by rain and road salt.

porksboy
porksboy Dork
11/6/09 7:40 p.m.

I have used Permatex formagasket in a tube as a sealing compound in a pinch. It also works well when you have to reuse a crusty coolant hose on a crusty fitting in a pinch.

carguy123
carguy123 Dork
11/6/09 10:34 p.m.

Thanx guys. Now I know what to do, which is blast the other 3.

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