Doug Fattic 

As a pro painter I have a marvelous pressure pot sandblaster that recycles the media after separating out the dust. A pressure pot sandblaster is better than the more common (and cheaper) pressure type that has to use more air pressure to work efficiently. The pressure pot type puts out more volume of media at half the pressure. I only use it after chemically getting off most of the paint. I wouldn't want to use it to entirely strip a frame of good paint (like a urethane enamel) if it had light tubing. I like to use my pressure washer to remove the chemical stripper before sandblasting whatever is left.

There was a discussion on the Classic Rendezvous list recently about what media should be used in sandblasting a frame. I didn't participate except to say I've learned what methods are aggressive enough to do the job but not so much as to harm the frame. I certainly wouldn't appreciate somebody telling me what I should be doing/using when they don't have any experience themselves. That discussion ended with many realizing there are different approaches to taking off paint and each painter has learned what works for them.

In Niles where I live there is a furniture restoration business that has a big dip tank that I sometimes use in the winter when I don't want to be outside chemically stripping. They dunk the frame in a big tank and leave it overnight. I've paid somewhere between $20 and $40 for this service. I think they make up the price each time I go. You guys might look to see if that kind of business is in your area. When you consider the cost and mess of doing it yourselves, the price is reasonable.

Happy Feet

Some interesting ideas...

I've stripped quite a few frames with Circa 1850 furniture stripper. Coat sections, let it bubble, use a scraper. Usually I have to wire wheel afterward.

Recently I discovered a local U Blast sandblasting shop where I can do my own stuff with various medias. Can be a bit pricey if you don't pre strip because the original paint is often quite hard, but with a rough pre strip it goes fast and pretty.

I've not seen aircraft stripper in stores up here in Canada.

robertorolfo

Doesn't anybody worry about possibly taking off too much frame material? Some of our frames are significantly less than a mm thick in places, and when you read about the various Columbus tubesets and the differences that .1 mm makes... From my limited experience in metal work (which included some sandblasting), amounts that small could easily be removed by a mistake or some overzealous removal.

BFisher

Sand will remove material. But there are other media that are much less aggressive. I doubt any serious finisher uses actual sand. Sand is used for lettering on granite monuments and tombstones, stuff like that.

robertorolfo

Good to know and thanks for the info. As mentioned, my experience was limited (sand blasting in a dental lab where you could easily put a hole in a casting/crown if you weren't careful).

BFisher

Glad to share.

Wileyone 

Try Carquest or NAPPA.

SJX426 

Did I read an echo!?

Doug Fattic 

That is what I was saying in my post #26 . The reason I chemically strip a frame before sandblasting is to reduce the amount of sandblasting that can potentially damage a frame. I've been painting bicycle frames professionally for 45 years and have learned what effect sandblasting can have. Both the type of media and sandblaster (and the pressure setting on the sandblaster) has to be effective enough to remove paint but not so aggressive as to take off too much. Paint tends to collect in corners (like lug shorelines or braze-on bits) so if one keeps blasting until every bit of paint is gone, then it is possible to remove too much metal in surrounding areas.

robertorolfo

Just a follow up for everyone: is there any way to strip paint that is on top of chrome without compromising the finish of the chrome? I assume the chrome has to be re-polished at least...

nlerner

I have found that when you strip paint off of chrome (which I just did), what’s underneath is not highly polished and better left painted. And that chrome is really hard and won’t be affected by paint remover.

leftthread

Back in the day I worked at a foundry that cast sculpture- your basic life-size bronze stuff. We used glass shot in the blaster to clean the bronze before assembly and fine metal finishing.