Lead leached onto Resin roof - Cleaning suggestions

[paro]

Hi All - My lead capping -- despited being oiled -- have leached onto the resin roof.  I've tried some acetone which looked like it might work and does dull it down but the marks are still there.  Has anyone any suggestions for what might take it off?

Because I've top coated it I'm pretty sure you're not supposed to go over the top like you can the resin as it will just delmainate because of the wax content. 

 

Thanks, Paul

[Conor]

Rub down and another layer of topcoat along the affected area. Assuming the lead has stopped leaching. Guessing some parts not fully coated in oil.

[paro]

When you say rub down you mean sand it down to the resin? I was hoping to avoid that if I can.

[Conor]

No just a light rub over with something like 180 grit paper. Just take the shine off the existing coat and something for the next coat to key to. I use a random orbital sander with 180 paper in it and only takes a few mins.

[paro]

Ah okay, that's good I was concerened I'd have to take off all the top coat around the edges. Thanks.

[SteamyTea]

Ideally you will want to use a self-etching polyester resin as part of the top/flow coat mix.

You really do need to remove most of the existing top/flow coat. Unless you know what the 'flavour' is i.e. make and mixture.

 

Proper repair work is often harder than redoing it.

[Russell griffiths]

Stop looking at it, and go to the pub. 

[SteamyTea]

24 minutes ago, Russell griffiths said:

Stop looking at it, and go to the pub. 

It will soon be winter and in darkness for 15 hours.

[paro]

20 hours ago, SteamyTea said:

Ideally you will want to use a self-etching polyester resin as part of the top/flow coat mix.

You really do need to remove most of the existing top/flow coat. Unless you know what the 'flavour' is i.e. make and mixture.

 

Proper repair work is often harder than redoing it.

Thanks. I only did this a few weeks ago and have some left over. If so would an acetone wipe and a light coat with the top coat work?' I used regular Cureit.

[paro]

20 hours ago, Russell griffiths said:

Stop looking at it, and go to the pub. 

I know you're right, but I'm going to wake up every morning and stare at it out the bathroom window whilst brushing my teeth annoying myself for not fixing it. 

[SteamyTea]

8 minutes ago, paro said:

If so would an acetone wipe and a light coat with the top coat work

Not for me.

It really needs grinding down to the GRP substrate, cleaning and then reapplying.

 

Polyester resins generally bond to other polyester resins quite well, before they are fully cured (a day or two).  After that, they are not to good as the free styrene has boiled off, even as low as 10°C.

This is partly why self-etching resins were created, it made repairing boats easier.

Wax additive, which makes for a nicer finish, is paraffin based (usually) and works as a release agent. A light sanding will, initially, seem to be good enough, but generally, over time, delamination will take place.

 

I used to make steam room from GRP.  Steam and thermal cycling is how resins are tested for longevity (with UV lights).  Took me quite a while of seeing failures before I got a decent combination of resins that could be cycled reliably, every day, for a few years.  When I left the company, the guy who took over decided to change just one component, failures started in weeks.

I am still smiling about it over 30 years later.

[paro]

Thanks for that. This is kind of what I was expecting if there was no way to clean it off. 

 

I am a little concerend by your fully cured after a day or two comment as I ended up applying in several stages with multiple layers over the course of about a month due to the weather. First coat was just a light resin to coat the boards as trying to keep the flat roof dry was a nightmare. Then separately I bandaged all of the GRP trims, screws and boards. Third was the main matting and then finally the top coat. Each layer was well sanded between coats and acetoned but there was a about a week between each.

 

Re the stains I think I'll take the ignore it approach for now.  I can always come back to it once I've got the main build done.