Oxalic Acid mix recipe - rust removal, GRP cleaning

[willk]

I've used oxalic acid in a mix for cleaning over the years but was never very particular about mixes and so on. I was a bit more scientific this season and kept a record. Cleans rust stains and returns yellowed and stained GRP to original colour in 10-15 mins, washes off with a light pressure wash.

1 litre of luke warm water
200g Oxalic acid powder (ebay)
50mls car wash detergent (any mild liquid detergent)
Wallpaper paste powder (to required consistency)

Add the acid to the water. Slowly add paste powder until mix starts to gel. Go short and leave it a while - it thickens for a few minutes. Then add detergent. Brush on, leave 10-15 mins and pressure wash off. Avoid galvanised metals, chrome etc. Wear PPE. Safe on stainless steel. Above mix will cope with a 5-6m RIB hull and console. If staining is heavy, or there is residual grime, rub gently with a rough cloth or other textured but soft material and the detergent will help lift the crud and let the acid go to work.

[boristhebold]

Does it work any better than Y10 or Hempel Gel Coat Cleaning Powder

[GordyP]

Y10 is basically just the same, it’s just 100 times more expensive! [emoji23]

[Bushrider]

Originally Posted by GordyP

Y10 is basically just the same, it’s just 100 times more expensive! [emoji23]

Should have known this before .. [emoji15]

[Sloopinn]

Is it ok to use on tubes that are only a couple of years old,or is it best on old very badly stained tubes? I’ve read so cleaners are very aggressive and take layers of hypalon off. For this reason would I be better using a milder cleaner than acid? Was told by manafactuer tubes if looked after should last 20 years hence don’t want to start removing layers in the early years.

[willk]

Originally Posted by boristhebold

Does it work any better than Y10 or Hempel Gel Coat Cleaning Powder

Same active ingredient - only the concentrations vary. I suspect that 20% is fairly high by commercial standards. This mix removes yellowing from GRP in a minute or so and deals with rust stains very rapidly. I'd suggest a gentle brush around the worst rust - like a bolt head or crevice.

I've never noticed it have an effect on tubes where there was local splashing. I can't say it wouldn't cause discoloration because I just don't know. It is more of a bleaching agent/rust remover than a cleaner, hence my addition of detergent to shift basic grime while working.

And yes - very cheap. Apparently, having an affinity for cheap cleaning products is one of the primary tells for Scottish Ancestry.

[beamishken]

Most marine cleaning products are based on readily available common ingredients with the addition of some very expensive water and occasionally colours or thickening agent (hence the wallpaper paste) its pretty easy to find out whats in each product as the manufacturer has by law to produce a chemical data sheet and most publish online often somewhere spurious you just search for the product name and MSDS and usually it pops up. I have noticed though that certain countries alowed the details to be a bit vague (to protect the products identity) but other countries are obviously more strict and require more specific data.
I found the data sheet for rydlyme which is weak hydrochloric acid which is clearly identified on the Australian msds sheet but not on the US data sheet.
Barnacle buster is phosphoric acid grunt is phosphoric acid y10 is oxcalic acid all of which can be bought off ebay for a fraction of the cost of the "marine" stuff

[Orwell boy]

well done for putting the recipie up ,personally i skip the wallpaper paste and go with the garden sprayer ,seems to virtually work on contact , also use to rejuvinate the hardwood decking this time of year

[willk]

Originally Posted by Orwell boy

well done for putting the recipie up ,personally i skip the wallpaper paste and go with the garden sprayer ,seems to virtually work on contact , also use to rejuvinate the hardwood decking this time of year

Bit aggressive on a galv trailer for my liking.

[Orwell boy]

Originally Posted by willk

Bit aggressive on a galv trailer for my liking.

Have you noticed any lasting effects on trailer or other metal ?? ,personally i have got all gloved up as the word acid makes it seem like its needed ,treated it with extreme care ,but tbh have never really seen any negative effects ,be interesting to see some potetial consequences, as never seems to be too many warnings, even on the manufacturers packaging .

[willk]

Originally Posted by Orwell boy

Have you noticed any lasting effects on trailer or other metal ?? ,personally i have got all gloved up as the word acid makes it seem like its needed ,treated it with extreme care ,but tbh have never really seen any negative effects ,be interesting to see some potetial consequences, as never seems to be too many warnings, even on the manufacturers packaging .

I've had limited skin contact and my clothing has taken a few hits with no major damage. That said, I've seen galv patches cleaned back to shiny and new - galv is sacrificial so no desire to reduce protection on my part.

Concur that "acid" spooks some folks. There's a big difference between some acids - i.e. Vinegar and Sulphuric. Oxalic acid is fairly benign, but I make sure to keep it off my skin and trailer and out of my eyes.

[beamishken]

As willk says the mention of Acid does tend to alarm some folk but it comes from many plants that we eat including spinach beets kale and rhubarb so probably no more hazardous to our health than a large helping of grannys rhubarb crumble

[The Black Pig]

I have used this today for the first time and yes it works, cheaper than y10 and you can get volume which is nice to have in the garage on stand by, I found you need to agitate on darker rust stains but it all comes off eventually