Removing powder coating finish from metal.

[CarlParticipant @carl48656]

Has any one had any success removing a powder coat finish from metal ? I have been quoted £50 for blasting from a powder coating company ( bicycle frame and forks) Thank you in advance

[CarlParticipant @carl48656]

[old martParticipant @oldmart]

Paint stripper might work, but the modern formulations are not as good as the older types. Only a test area can tell.

You ought to find out what type of blasting would be used, bicycle frame tubing is very thin wall.

Edited By old mart on 08/01/2021 15:15:51

[Andrew EntwistleParticipant @andrewentwistle]

I have succcessfully used paintstripper to remove powder coating completely, The modern formulation is not as potent as original Nitromors but if covered with clingfilm or foil etc and left for an hour or more still does the job in one or two applications.

Edited By Andrew Entwistle on 08/01/2021 15:21:23

[Jeff DaymanParticipant @jeffdayman43397]

Some powdercoat is made of a PE type thermoplastic and can be softened with a heat gun and scraped gently / peeled off. Difficult in nooks and crannies but sometimes it comes off in big sheets. If it does, it won't take long to strip it yourself. If it doesn't soften with heat or solvent type chemicals, 50 pounds for blasting may be good value – just depends on what value you place on your time.

Should mention if heating thermoplastics, or using chemicals, be sure to have plenty of flow through ventilation and wear a respirator mask rated for VOC's if possible,

[Clive FosterParticipant @clivefoster55965]

My experience is that blasting isn't terribly effective at removing good powder coating unless very agressive media is used. Which may not be a good idea on thin wall bicycle tubing.

A couple of weeks back I had to remove powder coating from inside the brake drums of a pair of motorcycle wheel hubs that had been blasted and coated without appropriate masking. My Guyson blaster barely took the shine off it. But I use a relatively small grit size as must of what I do is for pre-paint preparation and lighter cleaning so I want to avoid surface damage. Ended up setting them turning in the lathe and carefully scraping the coating off. Very much not the way I'd choose to work but needs must.

Clive

[Bo’sunParticipant @bosun58570]

Posted by old mart on 08/01/2021 15:13:50:

Paint stripper might work, but the modern formulations are not as good as the older types. Only a test area can tell.

You ought to find out what type of blasting would be used, bicycle frame tubing is very thin wall.

Edited By old mart on 08/01/2021 15:15:51

Tube thickness will depend on the bike quality. Cheap bikes will almost certainly be high tensile plain gauge steel (non-butted) so not much of a problem there. Not sure that butted cro-moly would be too much of an issue either. I'd be a little wary though, with hydro formed aluminium. My Specialized S-Works M5 sounds pretty thin in places when you tap it.

[Andrew TinsleyParticipant @andrewtinsley63637]

My problem has always been trying to stop the damn stuff falling off, you must have had a top notch company powder coating company do your frame!

Andrew.

[Mark RandParticipant @markrand96270]

Take it to your local powder coating firm. They'll burn it off in their oven.

[CarlParticipant @carl48656]

It's a Specialised Stumpjumper, steel tube version, double or triple butted but not sure how thick the walls are. Some one on Youtube demonstrated gasket remover, CPC i think, googled the active ingredients and you wouldn't want to do it indoors.

Some finishers dip them i think but the one who got back to me didn't offer that. Would find out the media used if i went down that road. Trying to keep the costs down and of course like to do as much as possible myself ! Plan to paint, easier to touch up scratches and knocks than a powder coat.

[Ex contributorParticipant @mgnbuk]

The company I used to use for powder coating motorcycle parts used to bake previously coated bits before removing the old coating by grit blasting. Baking the parts apparently made the coating brittle & easier to remove.

You don't say what type of bicycle frame you have, but for a "high end" road bike frame I would be wary of heating it, though. My former employer was a competetive cyclist (cyclo cross) & built bikes quite regularly – apparently the frames are designed to "whip", storing & returning the energy imparted to them by the rider. They eventually work hardened & lost this "whip" ability, which could be returned by having them heat treated – which destroyed the finish. He chose to build a new bike around a new frame rather than go down the heat treatment route. IIRC he went on to titanium frames rather than steel.

Nigel B.

[Joe McKeanParticipant @joemckean81940]

Only every used it on smaller parts but Acetone usually works wonders

[Oily RagParticipant @oilyrag]

Get some methyl dichloride (the original chemical in Nitromors) available in 1 litre and 25 litre quantaties from ReAgent Chemicals Ltd,. BTW they will only supply to a business address!

It is the only way to decarbonise cylinder heads and removes petrol varnish from carburettor bodies!

Martin

[Phil PParticipant @philp]

Frost Auto restoration used to sell a powder coating dissolver but I cannot see it on the website now, they do have a product called "Tank Strip" that claims to remove any coating from any surface.

Phil

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