Framebuilders - Sanding down paint on old frames

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Cablestein
07-05-09, 04:50 PM
Hi

I have a couple of old steel road frames I'd like to re-paint. A friend has an air compressor and airbrush kit that he'll lend me.

I've started manually sanding one frame with 80 grit sandpaper and a small wire brush for tight spots. Oh man does it take a long time! Basically each length of tube takes an hour to completely sand down to bare metal. Each dropout takes about one and a half hours. Each small boss (for fenders, etc) takes about half an hour. In grand total I can see myself spending 12 hours sand-papering one frame.

Now I can see why sandblasting is so effective!!!

Other than sandblasting, what's the best alternative to manual sanding?

Using an electric palm sander?

Maybe sanding/grinding wheel attachments on a standard drill?

retrofit
07-05-09, 05:09 PM
Jasco Premium Paint & Epoxy Remover...the frame will be done in minutes.

stan
Cablestein
07-05-09, 05:31 PM
Ahaaa forgot about that, a paint stripper!

Kind of don't want to use chemicals though.

How safe are they? Is there a lot of liquid in the end to dispose of?

Scooper
07-05-09, 07:10 PM
Jasco Premium Paint & Epoxy Remover...the frame will be done in minutes.

stan
+1

Jasco Premium Paint & Epoxy Remover makes really quick work of stripping a frame of paint. It even works well on powder coated frames.

Just use it outside in open air and use protective gloves. Read the MSDS (http://www.homaxproducts.com/MSDS/pdf/0201_1_0202_1_0203_1_0204_1.pdf)!
NoReg
07-05-09, 11:03 PM
Palm sanders for the most part are less effective than hand sanding. Their main advantage is a very even distribution of the scratch pattern for finish sanding. Some random orbital sanders are pretty fast. Often you can improve your removal rate hand sanding by experimenting with different papers. 80 grit is coarse but has less points for rapid removal than finer paper, so experimenting with coarser and slightly finer paper.

Also back some strips with filament tape so they are really tough and bootshine the tubes. Be careful about getting heavy scratches in the metal doing that though. You can also hold the strip down under your thumb and pull it through. Or get some cloth backed rolls of 1".

Some wire wheels are pretty effective. You want a reasonable size one being driven by something like a 4" grinder. A 3m Scotchbrite type wheel can be very agressive.

Not saying chemicals or media blasting wouldn't be better...
squirtdad
07-06-09, 12:32 PM
+1 on stripper....also C&V used to have a good section on frame painting.....do a search on post by Dr. Deltron for some good input also
rm -rf
07-06-09, 01:05 PM
Use kitchen plastic wrap over the paint stripper. It won't dry out as fast, and you'll be done quicker and use less stripper.
Cynikal
07-06-09, 01:21 PM
Why remove the old paint. I bet that the primer on the bike is better than what you can do at home. Just rough it up and use it as a primer.
w98seeng
07-07-09, 08:07 PM
Why remove the old paint. I bet that the primer on the bike is better than what you can do at home. Just rough it up and use it as a primer.

Exactly. Only sand the areas that are rusted or scratched. Level out the chips and scratches and paint over the old paint. Use 220 grit paper before painting.