The place for technical discussions about GA and flying.
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By Red
#1818368
I need to get the paint off a GRP Cowling and remeber being told not to use Nitromors as it will attack the gel coat.
But, this was in the days when Nitromors had some sort of nasty stuff in it that the EU banned I've looked all over the interweb and can't find any info relating to the new formulation, anyone know if the new stuff is ok on GRP?
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By MikeW
#1818386
It was dichloromethane (methylene dichloride, old name) in Nitromors. Yes I can confirm it did attack gelcoat :(
It's now only allowed in supposedly controlled professional products.

I think the most common alternative in DIY products is benzyl alcohol (e.g in B&Q and Wickes own brands). It is MUCH less effective and I don't think it would touch two pack paint let alone gel coat. I've only used it on conventional paint and single component polyurethane varnish on wood, it works but very slowly and needs a lot.

PS just discovered Nitromors new product uses different chemicals, see https://www.andrewscoatings.co.uk/wp-co ... -sheet.pdf
I haven't used it. There's a review here https://skill-builder.uk/nitromors-the- ... ou-to-read
By Red
#1818774
Thx for replies, couldnt find a definitive answer so am currently (hopefully) about half way through sanding it off...the dust has given me a cracking headache :( so will be wearing a mask today
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By skydriller
#1818963
Red wrote:.the dust has given me a cracking headache so will be wearing a mask today


:lol: :lol:

Not laughing at your headache and not singling out "you"...

... but it is kinda funny that (to me at least) in this bizarre "PPE" world we find ourselves in, you would wear a mask to go shopping where there isnt any evidence that it will protect you ( from C19) and are legally in some cases obliged to wear one...yet when specificly doing something obviously hazardous where a mask is proved to protect you (from dust) you dont consider wearing one.

Stay Safe, SD..
By Peter Kelly
#1818992
For larger components grit blasting is the way to go. It’s a commonly used process in the marine industry for removing old antifouling. It is however quite aggressive.

On small lightweight aeroplane components a high quality orbital sander is the way to go. You’d be amazed how much quicker a £400 Festo sander removes paint compared to a £49 B&Q one.
By Red
#1819126
SD, Its ok I deserve the title silly bu99er at times
PK..You knew I had the B&Q one didnt you :x (and your right its rubbish)
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By Paul_Sengupta
#1819127
Peter Kelly wrote:For larger components grit blasting is the way to go. It’s a commonly used process in the marine industry for removing old antifouling. It is however quite aggressive.


As I understand it, they use walnut shells for blasting aeroplane paint.
By cockney steve
#1819207
AIUI, Aircraft aluminium skin -sheet is actually coated with a thin layer of alloy which abrasive is likely to wear-through. Boat Gel-coat tends to be quite thick, plenty of "meat" for sand/grit/nutshell blasting. but Aircraft are built down to a weight, so it's likely a gel-coat (which has little strength, it's predominantly cosmetic) -is extremely thin. best to sand down until the original primer becomes opaque-or, if it's virgin gelcoat, use a suitable detergent and Scotchbrite pads to clean and key the surface.
Just my opinion.

I have a Rupes Super-stork half-sheet sander just rebuilt it after about 45 years' hard use in the Motor-trade. most spares still available!, Bed with rubber pad spring clamps and rubber paper-grips,ETC. I'm confident it'll see me out! :D
By oldbiggincfi
#1819278
Brake fluid is pretty good at attacking most paint .
Worth trying on a small patch .
Good thing, can be washed off with water.
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By Charles Hunt
#1820005
What is the symbol of a circle with three blobs inside it that appears on this thread but nowhere else?