Quote:
Originally Posted by Steve Rooke
One thing that concerns me about using a derusting tank is Hydrogen embrittlement. I do not understand it, but after doing some reading on the web I would he hesitant in using it on critical parts such as wheels or a chassis. Apparently it is a major concern in the electoplating industry. Anyone the wiser?
That said, I have no problem using it on panels or minor parts. Its the cleanest way I know of stripping paint. if I only could build a bigger enough tank to fit my cab into.
Steve
|
Steve,
Whoo............... A high tech thing for Ye Maple Leaf Up!
I think that this problem (only) relates to alloys and not to regular iron/steel. Hydrogen Embrittlement occurs when stripping paint from an alloy, using some chemical strippers which are methylene chloride based (chemical paint stripper). NOTE: The alloys can include high strength steel but these would be rare in 1942, and would be like the special cross member in my Ford Capri convertible.
If embrittlement occurs, then the alloy piece in question can lose it's physical strength, and cause a catastrophic failure. Most chemical strippers have this compound in them. It affects predominantly aluminium and magnesium alloys.
It is critical in stripping alloy aircraft parts that the correct stripper is used. It was a very expensive lesson for my previous employer to learn that they had made a few million in parts worthless by stripping with a no frills stripper instead of media blasting them!!!
The damage by chemical stripping: It is sub-atomic and the parts look normal, but their strength is about ten-fold less!
As every alloy is made differently, I am personally wary of chemical stripping and my best solution to this issue is use plastic media blasting. Some blasting can be detrimental too as it can 'case harden' metals and intoduce micro-pitting which will lead to cracks and corrosion. (my personal dislike of sandblasting relates to this)
Some of you have heard of 'pickling' (in alloys) then Hydrogen Embrittlement with chemical stripper is the reverse!
It is a large subject but hopefully this will enlighten readers a bit more... It appears that the person on the WWW whom you have taken your data from does not understand what happens either.. unless a wheel contained alloy, it is impossible that it would be affected by hydrogen embrittlement. As for other parts ie Chassis and the like, they would primarily relate to alloys, not steel....lest of all your good old iron CMP chassis.
Ian