Oxalic Acid

[spidy]

I have just bought some oxalic acid for cleaning up my gel coat. Does any of you so called experts know how to mix and use it, AND if its a so called acid how do you neutralize it after use to stop it eating the grp away. /forums/images/graemlins/laugh.gif

 

[geoffatstanpit]

You need to make up a 10% solution in warm water. A bit of wallpaper paste makes it thicker so it stays on the job for the minute or two it takes to miraculously remove the stains.

It isn't a very strong acid (like lemon juice) so it won't eat your gelcoat. It is a poison though (22g would kill 50% of 60 Kg people) so don't leave it lying around in anything that might make it look like a drink!

 

[mariog]

I have been using it for years. I wet the deck then sprinkle the oxalic acid on the deck and using a broom I just brush it lightly to distribute it everywhere after about 10 minutes I scrub the deck with the brrom and then rinse ir thoroughly with frech water. and voila !!! deck is clean and white. then I wash the deck with liquid soap containing silicone to seal the pores again.

 

[tillergirl]

The 'classic' recipe is 25 grams to 500cc of water. Neutralised by water.

 

[alf1]

I think it comes from rhubarb leaves

 

[VicS]

[ QUOTE ]
I think it comes from rhubarb leaves

[/ QUOTE ] I don't think it is obtained commercially from rhubarb leaves but they do contain it, as do several other plants.
See The Rhubarb compendium for all you could wish to know about rhubarb

 

[Gordonmc]

I was using it last weekend to clear off rust stains on the topsides of my carvel planked hull. One tablespoon in a litre of water sponged on. Left for five minutes then rinsed off with sea water.
As other have said thickening would keep it on one place for longer, but I found it wasn't necessary.
Good stuff.

 

[Gin]

That sounds like a good solution(sorry!).

Can you suggest a proprietary name for the silicone soap?

 

[boatbuilder]

The only problem you have now is that due to the silicone getting into the gel coat you will find it very difficult to do any gel repairs.
For this reason no silicone products should be used on gel coats. indeed in our yard they are banned.

 

[Gunfleet]

It doesn't tell me the thing I've always wanted to know about rhubarb... how the hell did they work out the stalks weren't dangerous? Was there a tribe of sacraficial apprentice chefs going round eating things? 'Fred's gone to the rhubarb leaves... try the stalks on Charlie and if that doesn't kill him we'll try him on some Akee'

 

[spidy]

Many thanks for the straight forward reply's, thought we were sailors not chefs, (but that opens a whole new ball game doesn't it) /forums/images/graemlins/laugh.gif