Oxalic Acid - I don't get it!!!

makingplansfor

makingplansfor

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Having read about the almost miraculous properties of oxalic acid on grubby gel coat on this board, I have persevered for the 3rd year without it making any impression on a variety of stains from rust streaks to exhaust stains! I have tried it at different temperatures, with and without wallpaper paste, triple the recommended strength without it doing anything except burning hands when it gets inside gloves!

Oh well, hard work it is then.............
 
makingplansfor said:
Having read about the almost miraculous properties of oxalic acid on grubby gel coat on this board, I have persevered for the 3rd year without it making any impression on a variety of stains from rust streaks to exhaust stains! I have tried it at different temperatures, with and without wallpaper paste, triple the recommended strength without it doing anything except burning hands when it gets inside gloves!

Oh well, hard work it is then.............
Click to expand...
Try Auto Glym engine cleaner works a treat.
 
Oxalic acid won't do anything to exhaust or oil stains. What it will sort out are rust stains and the similar coloured stains that you sometimes get along the waterline. Needs to be about 10 Celsius or above (I've found) and just keep painting on until the stain disappears. Only thing I can think is that maybe you have got a layer of wax/polish over the top of the stain. Give it a light going over with Farecla G3 or similar over the stains and try again. It's never failed for me. In fact I usually put a coat over the whole of the topsides every year, leave for a couple of hours/overnight and then hose off. It makes an amazing difference. I now don't bother with the wallpaper paste, just a bit of washing up liquid.
 
makingplansfor said:
Having read about the almost miraculous properties of oxalic acid on grubby gel coat on this board, I have persevered for the 3rd year without it making any impression on a variety of stains from rust streaks to exhaust stains! I have tried it at different temperatures, with and without wallpaper paste, triple the recommended strength without it doing anything except burning hands when it gets inside gloves!

Oh well, hard work it is then.............
Click to expand...

Not sure what you are doing but it has always worked for me in many forms. This year I just mixed with warm water and sprayed on, 30 minutes later hosed off and job done. I am in Plymouth and could bring you some of my acid to try. PM me if you like and we could try to get together.

Yoda
 
+1 For all of the above.

Temp. needs to be above 10C and 20C or more is great
Time can be as short as a couple of minutes at 25C or an hour at 10C (very marked difference)
Penetration will be helped by a drop of washing up liquid and removing any wax coating (I've never had problems with wax coating)

Only reason to thicken the solution is to keep it in contact with GRP longer (i.e. On side of hull) instead of just running off.

It will remove rust stains
Great for yellowing around waterline on white GRP hull
It won't do much for exhaust stains (mainly ground in soot and some oil etc.)

On the bright side, Y-10 and other marine products wouldn't have worked for you either. So at least you spent less to get the same result using oxalic acid.
 
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JAT said:
Very interesting..... I've never used it...but I have friends that swear by it. Could it be the other ingredients make it work better in this poducts form?
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The Isopropanol (IPA) will break down surface grease, so help the acid to get to the stain. It probably has surfactants as well. You can easily replicate this with detergent in the mix, or before.
 
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alahol2 said:
From the data sheet...

2.0 Hazardous Ingredients
Description CAS # % TLV UNIT
Isopropanol 67-63-0 4.5 400 PPM
Oxalic Acid 144-32-7 4.5 N/A
Non-toxic Ingredients 91.0

So, oxalic acid
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And the mystery "91% Non-toxic Ingredients"........ Water

Boiling point looks about right for 5% IPA and description is "Water-based cleaner with viscosity booster". So water, oxalic, IPA and a thickening agent. So save your money and buy some oxalic and vodka. Apply oxalic solution and drink the vodka until you don't care about the state of the hull.
 
makingplansfor said:
Having read about the almost miraculous properties of oxalic acid on grubby gel coat on this board, I have persevered for the 3rd year without it making any impression on a variety of stains from rust streaks to exhaust stains! I have tried it at different temperatures, with and without wallpaper paste, triple the recommended strength without it doing anything except burning hands when it gets inside gloves!
Click to expand...

Not sure how this applies to you in terms of using it, but Y10 is oxalic acid with a sort of jelly which allows decent contact and stays wet wet for a decent period of time. Have seen people fail with it, but do so because they have used it as you would a bottle of Jif. Instead Y10 needs to be slapped on reasonably thick, allowed to sit for 5 or 10 min, but washed off before it dries out.

Presumably wallpaper paste will also allow similar properties - ie. keeps it wet and thick?
 
Yes it's got to be a warm day for it to work. I did consider mixing up my own oxalic acid/wallpaper paste mixture but as a pot of Y10 (£10.95 from Force 4) lasts me a couple of years it didn't seem worth the effort.
 
Certainly in the Med in Summer, oxalic acid at 10% plus a drop of washing up liquid shifts rust stains on GRP almost instantly - like something which is excellent at shifting rust stains!

It doesn't do much with the other stains I have tried but I bought it for rust so I'm happy!

Richard
 
parsifal said:
Yes it's got to be a warm day for it to work. I did consider mixing up my own oxalic acid/wallpaper paste mixture but as a pot of Y10 (£10.95 from Force 4) lasts me a couple of years it didn't seem worth the effort.
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I only thicken oxalic solution on very rare occasions as it is normally pretty hot when I need to use it. Y-10 can be a bit of a sod to remove in very hot weather if allowed to dry. You get an awful lot of oxalic acid for £11 and it is very handy to have.

I made up 500mls last year for the guy on the boat next to mine, he was about 19 and looking after a brand new Oyster 575. The owner was due to arrive the next day and the lad was a bit worried. Someone had left 4-5 gas cylinders lying around he cockpit for several days and the brand new teak was covered in rings. I think it was being readied for the ARC and someone had delivered them, then switched out the used ones and put them on a clean bit of deck. Looked as if someone was trying to draw the olympic logo in the cockpit of a £1m boat. He was so relieved when I checked back a few hours later, not a sign of any rush stains left. Well worth having some on board to clean up stainless, GRP, teak.
 
RichardS said:
Certainly in the Med in Summer, oxalic acid at 10% plus a drop of washing up liquid shifts rust stains on GRP almost instantly - like something which is excellent at shifting rust stains!

It doesn't do much with the other stains I have tried but I bought it for rust so I'm happy!

Richard
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+1 for that mixture. I found wallpaper paste reluctant to dissolve in the acidic solution , so washing up liquid has a similar result- wets the surface -and you can see where you put the mixture. (bubbles). I apply it with a 3 inch paint brush on a short broom handle.
Wear rubber gloves... it stings on skin....!

I probably make it stronger than some folk, since in Scotland during the sailing season, anything over 15C is a heatwave....

Graeme
 
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