How to safely strip paint from GRP?

[nemodreams]

If caustic soda is ok - then a very good stripper can be made cheaply from caustic soda ( mixed into a solution first ) and wallpaper paste. Slob it on and cover it with cling film. The paste keeps it thick and the cling film stops it evaporating.

Most paint stripper are better if laid over with cling film.

Most 'modern' recent formua paint strippers are complete ribbish. Even Nitormors Green tin stuff is pretty awful now - capared to what it was.

 

[SAMYL]

Which did you use? As I wrote, I have had very good results on GRP (cars and boats) with 220 but abject failure with 620.

It was the RemovAll 620 and it worked well - once I read and applied the directions correctly i.e. leave it overnight.

I think it was cellulose I was removing, it may not be so effective on other paint types like 2K or water based.

 

[JumbleDuck]

It was the RemovAll 620 and it worked well - once I read and applied the directions correctly i.e. leave it overnight.

Interesting. I gave it overnight as well. Must have been paint types, as you said.

 

[Marine Reflections]

Previous owner had a rather poor sign writing job done on the bow, painted, not vinyl lettering, irregular and at an angle, so I want to remove it and re-do it properly even though we aren't changing the name!

I'm guessing its ordinary black gloss paint - how do i strip this safely without damaging the gelcoat of the GRP hull?

I'm guessing that Nitromors will not be a good idea and a scraper is going to damage the hull for sure!

If you are going to strip it read post 5, as per usual VicS has nailed it.

I personally wouldn't use stripper at all, not because it won't work, it will, it's just the job can be done better and quicker without chemicals. A painted name on gel I would estimate would take under a minute to remove.

There is also the issue that stripping chemicals may cause the paint to bleed ever so slightly into the gel if it is porous, making removal of the colour difference slightly harder once removed. It depends on the condition of the gel when the painting was done, if it was accepting new guests or rejecting them.

I would use a scraper blade. Not the pull type of scraper, but the ones where you lock a blade into a holder, the type you would use when removing excess paint on glass from inside a window frame.
Like this one :

The blade needs to be polished (or dulled) on the edges with v fine wet n dry (2500 or so) so there is less risk of biting into the gel. If held at a low angle with short motions it will make short work of any 'above surface contaminates' without harming the gel. The wet n dry also serves to dull the blade to a level where there is no tiny nibs on the blade that may scratch the surface, in other words it is as flat as a pancake, well perhaps a bit smother than that!


With a little practice it is very easy, I have also used them for removing over spray on car body panels without eating into the paint surface.

It may be a good idea to lube the area with a spray of quick detailer or even something like furniture polish, this will assist the blade sliding and not biting
If you have good car paint panels don't watch this video, the guy hashes the job in my opinion, but it does show roughly (very roughly) how it's done.

https://www.youtube.com/watch?v=8i--i-AovdE

Ok, thinking about it, it is a bit of hassle to modify a blade just for this one job and for normal DIY perhaps stripper would be the way to go, just thought I would share, it's a handy tool.

 

[vyv_cox]

I've followed a few of these paint stripper threads as I'm looking for something to remove the anti slip paint form my deck.

Methylene chloride based strippers are not generally available for the DIY market but it is possible to buy it. I bought 5 litres of Starchem Synstrip on the internet, in most cases you need to tell the small lie that it is going to be for 'professional use'. I stripped about 5 or 6 layers of old paint off my decks very rapidly. The stripper does soften the grp but it was in such poor condition anyway that it didn't matter a lot. After washing down and leaving a few days it was hard enough for treatment with an orbital sander that has taken out any scraper damage. I wouldn't use it on topsides but for a deck that will be repainted it was perfectly OK.

 

[VicS]

If you do as Vyv and source DCM illegally ensure you have good ventilation ( no problem outside, but a serious concern if working inside or perhaps even under cover) and do not smoke. It's not flammable but the decomposition products in contact with hot surfaces or inhaled through a cigarette include highly toxic phosgene.

 

[vyv_cox]

If you do as Vyv and source DCM illegally ensure you have good ventilation ( no problem outside, but a serious concern if working inside or perhaps even under cover) and do not smoke. It's not flammable but the decomposition products in contact with hot surfaces or inhaled through a cigarette include highly toxic phosgene.

I think 'illegally' is a bit harsh. There are plenty of sources that don't require any false statement at all, e.g. http://www.amazon.co.uk/Starchem-Synstryp-Paint-Stripper-Litres/dp/B00A7RMPGS Fully agree about the precautions though.

 

[VicS]

I think 'illegally' is a bit harsh. T.

Perhaps i should have said "sourced illegal supplies" as its the supply to consumers than is banned under EU law.

1. Paint strippers containing dichloromethane in a concentration equal to or greater than 0,1 % by weight shall not be: (a) placed on the market for the first time for supply to the general public or to professionals after 6 December 2010; (b) placed on the market for supply to the general public or to professionals after 6 December 2011; (c) used by professionals after 6 June 2012.

 

[Ru88ell]

I have an old grp tender to fix up. The interior has been painted on the matting, so scraping won't work well due to uneven surface. The paint has flaked in some places but not others. Did anyone come to a conclusion on a paint stripper?