Oxalic acid for cleaning teak

[rafiki_]

Many apologies if this has been done to death, but a little help please.

Do I need to mask off the non teak areas before I use?

Do I need to neutralise before oiling?

 

[Kukri]

Oxalic acid is the poison in rhubarb leaves.

That is the main thing to keep in mind.

No need to mask off other areas; do wash down well after use.

 

[VicS]

General info with a links to instructions and safety info HERE

What are the "non teak" areas.

It wont hurt grp but it would be advisable to keep it off metal fittings

 

[rafiki_]

Brilliant, thanks both. It is the grp onto which the teak is laid that I was concerned about. I understand that this will not be harmed, but metal catches/hinges might?

 

[gjgm]

Many apologies if this has been done to death, but a little help please.

Do I need to mask off the non teak areas before I use?

Do I need to neutralise before oiling?

Might be my error, but I thought the acid brightened the teak, not cleaned it (or have I got the products the wrong way round?)

 

[pheran]

Might be my error, but I thought the acid brightened the teak, not cleaned it (or have I got the products the wrong way round?)

Certainly cleaned the teak decking on our Valk (and there was acres of it, or so it seemed). Never bothered with any other treatment, just clean water until the next annual clean. Raiki: are you sure you want to oil it? Something small like a handrail, perhaps but certainly nothing under foot

 

[Scotty_Tradewind]

I found OA excellent for cleaning and lightening the teak on my last boat but I also had some areas of single pack paint work which had the shine taken off it by OA.

In a diluted form it gets rid of green algae, rust and blood stains, but remember it is an acid, so the same precautions are relevant that you would use with a diluted bleach.

 

[macd]

It is the grp onto which the teak is laid that I was concerned about. I understand that this will not be harmed, but metal catches/hinges might?

Oxalic acid is also used for removing rust stains on stainless steel and for cleaning grp (it's the main constituent of Y10 gel), and so harmless to both those materials.

 

[VicS]

but remember it is an acid, so the same precautions are relevant that you would use with a diluted bleach.

Well yes the same precautions but bleach is in fact a strongly alkaline ( caustic) solution.

 

[Scotty_Tradewind]

Well yes the same precautions but bleach is in fact a strongly alkaline ( caustic) solution.

did I say anything to the contrary??

 

[longjohnsilver]

Certainly cleaned the teak decking on our Valk (and there was acres of it, or so it seemed). Never bothered with any other treatment, just clean water until the next annual clean. Raiki: are you sure you want to oil it? Something small like a handrail, perhaps but certainly nothing under foot

I frequently use oxalic acid, last time last week mixed with wallpaper paste on my hull, cleaned it up a treat. Also very successful on teak decks (without the wallpaper paste!)

I would agree that unless a very small area, or inside, definitely do NOT oil the teak, looks great for a week or two but then attracts all sorts of nasty muck and looks awful. I tried this on my rails so can speak from experience....

 

[gjgm]

Certainly cleaned the teak decking on our Valk (and there was acres of it, or so it seemed). Never bothered with any other treatment, just clean water until the next annual clean. Raiki: are you sure you want to oil it? Something small like a handrail, perhaps but certainly nothing under foot

Why do some cleaning packs have two treatments?

 

[pheran]

Why do some cleaning packs have two treatments?

Separate cleaner and brightener I guess. But you can bet you life that with all these overpriced solutions, good old Oxalic Acid will be in there somewhere. OA is, of course the very much cheaper solution. If I'd had to clean the deck of my (49ft) Valk with little bottles of Starbrite or somesuch, I wouldn't have been able to afford to go boating.

 

[rudolph_hart]

Separate cleaner and brightener I guess. But you can bet you life that with all these overpriced solutions, good old Oxalic Acid will be in there somewhere. OA is, of course the very much cheaper solution. If I'd had to clean the deck of my (49ft) Valk with little bottles of Starbrite or somesuch, I wouldn't have been able to afford to go boating.

http://www.wessexchemicalfactors.co.uk/products.htm

These people do 2-part cleaners for both teak and GRP. I've used both products every fit-out for the last 6 years and they really do work. I understand that the two products are now one and the same.

Part 1 is a 'saponifier' which is very aggressive (Marigolds essential) and really shifts stains and dirt -the run-off from teak is quite startlingly brown.

Part 2 is dilute Oxalic acid which whitens GRP and brightens teak.

The main thing to stress is not to use brushes on teak. Only a big, sloppy sponge is used to spread the each 10:1 diluted mix over the teak. Once it's rinsed and dried off, I leave it - is stays bright all season.

No commercial connection - just a happy user.

Hope this helps.

 

[Scotty_Tradewind]

http://www.wessexchemicalfactors.co.uk/products.htm

These people do 2-part cleaners for both teak and GRP. I've used both products every fit-out for the last 6 years and they really do work. I understand that the two products are now one and the same.

Part 1 is a 'saponifier' which is very aggressive (Marigolds essential) and really shifts stains and dirt -the run-off from teak is quite startlingly brown.

Part 2 is dilute Oxalic acid which whitens GRP and brightens teak.

The main thing to stress is not to use brushes on teak. Only a big, sloppy sponge is used to spread the each 10:1 diluted mix over the teak. Once it's rinsed and dried off, I leave it - is stays bright all season.
No commercial connection - just a happy user.

Hope this helps.

Sounds as if the 'startlingly brown' may be getting rid of a startlingly expensive amount of teak?

 

[pheran]

http://www.wessexchemicalfactors.co.uk/products.htm

These people do 2-part cleaners for both teak and GRP. I've used both products every fit-out for the last 6 years and they really do work. I understand that the two products are now one and the same.

Part 1 is a 'saponifier' which is very aggressive (Marigolds essential) and really shifts stains and dirt -the run-off from teak is quite startlingly brown.

Part 2 is dilute Oxalic acid which whitens GRP and brightens teak.

The main thing to stress is not to use brushes on teak. Only a big, sloppy sponge is used to spread the each 10:1 diluted mix over the teak. Once it's rinsed and dried off, I leave it - is stays bright all season.

No commercial connection - just a happy user.

Hope this helps.

Yes I've tried the Wessex products. tcm, erstwhile contibutor hereabouts, was quite a fan and posted several long and informative accounts on the care of teak. For anyone interested in the subject, it would be worth them searching the archives. TBH, I didn't find the Wessex stuff significantly better than straight OA although somewhat more expensive - and thats not just stinginess on my part.
In fact, I still have a couple of half-used bottles of Wessex on the shelf and persuaded myself back to AO which I used to buy in powder form in a huge airtight tin (probably 5kg) from a commercial chemical supplier.

 

[rudolph_hart]

Sounds as if the 'startlingly brown' may be getting rid of a startlingly expensive amount of teak?

Doesn't look as if it is. The teak in my cockpit is 17 years old now and, once treated, still looks as bright (and flat - no ridges) as new, and the Sikaflex seams are still almost level with the wood almost everywhere.

 

[gjgm]

http://www.wessexchemicalfactors.co.uk/products.htm

These people do 2-part cleaners for both teak and GRP. I've used both products every fit-out for the last 6 years and they really do work. I understand that the two products are now one and the same.

Part 1 is a 'saponifier' which is very aggressive (Marigolds essential) and really shifts stains and dirt -the run-off from teak is quite startlingly brown.

Part 2 is dilute Oxalic acid which whitens GRP and brightens teak.

The main thing to stress is not to use brushes on teak. Only a big, sloppy sponge is used to spread the each 10:1 diluted mix over the teak. Once it's rinsed and dried off, I leave it - is stays bright all season.

No commercial connection - just a happy user.

Hope this helps.

I also use the Wessex gear; there is certainly a difference between the two bottles, which is why I was wondering how come OA on its own is sufficient?

 

[pheran]

Sounds as if the 'startlingly brown' may be getting rid of a startlingly expensive amount of teak?

The 'no brushes', 'no pressure washers' advice is good whichever cleaner you choose. This is because teak is mistakenly regarded by many people as a hardwood - it isn't. Its a natural hybrid with the 'hard' bits existing a 'pips' surrounded by much softer wood. Hard brushing or pressure-washing tends to wash out the 'pips' leaving you with accelerated wear and deterioration and, eventually, an expensive bill for replacement. 'Sponge only' is good practice but even there, you still have the argument of only across the grain or with it!!

 

[rafiki_]

I plan to use a softish brush rather than a sponge. I have pressure washed the teak on the bathing platform before with excellent results. It did not appear to do any damage, but I have been persuaded to go the chemical route this time.