pre-NDT paint removal

[icepack]

I have a painted metal part, recently removed from service, that requires liquid penetrant inspection. I am aware that the paint must be removed, and that the method cannot "smear" the surface such that indications would be covered over by displaced metal. thus abrasive blasting, etc. is not acceptable. based on previous experience, i am wary of solvents that might damage the surface of the part. is it acceptable to pressure wash the part (not using any sort of abrasive in the water, just high pressure?)

 

[lostsailor]

icepack,
What is the material specification? What type of component are you talking about (service conditions)? What type of paint?
Regards,
RLS

 

[mw25]

I think this should be acceptable.

 

[icepack]

the materials are cast nickel aluminum bronze and titanium. the surfaces are machined. the paint is epoxy, and was applied with minimal surface preparation. so i don't think it will be that difficult to remove.

 

[James01]

HP water jetting may be OK. It would be better to use a solvent remover and thoroughly clean the part after removal of the paint.

 

[rorschach]

I would agree that something like a Methyl Chloride (or a replacement) paint remover should be used followed by a HP water blast should do the trick (you may have to choose your paint remover carefully for the titanium part, titanium does not like chlorides much)

 

[ndeguy]

The aerospace industry uses blasting with either lignocellulose amterial or materials derived from fruit stones eg plum, walnut, almond, hazel-nut etc., at pressures up to 1.7 bar (this is for aluminium alloy of hardness maximum 160VPN) followed by a light chemical etch.

Contact your penetrant materials manufacturer for further advise