trouble refinishing Campy wheels

Steve Meltzer · Post by **Steve Meltzer** » Sun May 13, 2007 11:46 pm

My friend and I have spent a lot of time refinishing the slotted Campy wheels on my 330 GTC. They look absolutely awesome, concours if I say so myself. However, when I had the new tires mounted, three of the wheels developed these very ugly paint blisters. Just like a damn zit. Anyhow, I wonder if the air pressure they used to fill the tires passed through the porous mag wheels and ruined our good work. Any thoughts on this? Would a tire sealer be of any value? I'm depressed. thanx steve

Jimmyr · Post by **Jimmyr** » Sun May 13, 2007 11:53 pm

Steve, were tubes used?

Harmony · Post by **Harmony** » Sun May 13, 2007 11:59 pm

Its all in the prep work. Have them sandblasted and powder coated.

Steve Meltzer · Post by **Steve Meltzer** » Mon May 14, 2007 7:42 am

no, we didn't use inner tubes, if that's what you mean. thanx s

Post by **tyang** » Mon May 14, 2007 8:53 am

My friend and I have spent a lot of time refinishing the slotted Campy wheels on my 330 GTC. They look absolutely awesome, concours if I say so myself. However, when I had the new tires mounted, three of the wheels developed these very ugly paint blisters. Just like a damn zit. Anyhow, I wonder if the air pressure they used to fill the tires passed through the porous mag wheels and ruined our good work. Any thoughts on this? Would a tire sealer be of any value? I'm depressed. thanx steve

Hi Steve,

Sorry to hear about your wheels. An inner tube would certainly isolate the air pressure from the magnesium. They're real porous, and probably get more so with age. The only problem with the latex tire sealers is they ruin the inside of the tire and wheel, and is a PITA to clean up when you take it apart. All that latex can also throw the balance of the tire off.

Did you use a primer coat before you painted the wheels silver? Although I don't know if that would have sealed them well enough, I'd like to know your process so other's don't have the same problems.

Thanks!

Tom

Steve Meltzer · Post by **Steve Meltzer** » Mon May 14, 2007 11:52 am

Wonder why the wheels would now lose air, when they didn't before the refinishing? The refinishing was a PITA, and now they're passing gas...jeez! (MY ex would say this is just retribution!)

Here's how I did them.

clean with degreaser

fill holes and nicks with bondo

sand with coarse grit sandpaper fairly soon thereafter

repeat at least once

sand again, 220-240 grit paper and then prime with high particulate primer

sand and repeat ad nauseum

we used 300-400 grit wet sandpaper, filled with one last coat of primer and repeated the last go ‘round before we painted with the 8:2:1mix of enamel paint, reducer and hardner. Paint at about 40 or so PSI.

We got some fisheyes on our first go ‘round, so we rewashed them in “Dawn” dish soap and water, then resanded with 220 grit till they were pretty dull. Then with 340 wet (used soapy water) and washed them thoroughly. Dried them in the sun and re-sprayed them with the same 8:2:1 + 2 drops of the anti-fisheye stuff and a clean air compressor hose.

steve

David Booth · Post by **David Booth** » Mon May 14, 2007 12:00 pm

Campagnolo is actually a client of mine and I was about to offer to pass your question on to them to see what they had to say. But they actually sold off the wheel portion of the business many years ago and reading the comments in this thread, I think you'll get a lot more useful information here than I could hope to geet out of Campy, Steve.

Steve Meltzer · Post by **Steve Meltzer** » Mon May 14, 2007 12:09 pm

thanx for thinking of me. I think I'll pull the tires, re-do them and use inner tubes. arggh. I'll keep you posted, it'll be awhile. s

airsanford · Post by **airsanford** » Mon May 14, 2007 1:13 pm

as I recall, there was a thread here some time back about this problem.

The gist of it was that the inner part of the rim (between the bead seating area) must be painted to seal the wheels.

If these wheels were made in the same manner as Campy's other period offerings, they were made of a magnesium/ aluminum alloy they called "elektron".

After they were originally stripped, they should have been treated with a chemical conversion process called magnadyne and then baked to drive all the moisture out of the metal.

Good luck,

Lee GTE 2811

Beech C-35

mark · Post by **mark** » Mon May 14, 2007 8:49 pm

I used zinc-chromate primer inside and out on the wheels before the finish coat. I think zinc-chromate is now illegal, but there must be a replacement paint?

Anyway, the wheels remain un-blemished and the tires hold air....

Mark

airsanford · Post by **airsanford** » Mon May 14, 2007 11:40 pm

Zinc chromate is still available from aircraft supply sources. Don't make a big deal about it, lest the environazis find out and take it away.

www.aircraftspruce.com

Lee, GTE 2811

Beech C-35