Grunt hull cleaner

[38mess]

I have used this in the past and it is very good, but at nearly 30 quid a pop it's a bit expensive,and I need 3 tubes for my boat, possibly 4. Are there cheaper alternatives that actually work? I don't want to use oxalic acid.
Thanks.

 

[Dino]

I bought a 5kg bag of Oxalic acid from a chemical company for £35. Mix with hot water in a 5 litre garden sprayer. Go around the hull twice. Does a great job and easier than brushing on a gel

 

[johnalison]

I think it depends on what sort of grime you want to clean. I normally start with a branded gelcoat cleaner such as those available from Starbrite or International, which all seem similar and make my skin sting. For most dirt this is sufficient but for yellow staining I end up using Yachticon anti-yellow which is similar to Y10 but more liquid and I assume is oxalic acid based. I haven't needed it for the last few years since we stopped going abroad but my 23yr old hull is as glossy as new and only needs waxing though I used anti-yellow for maybe 15 years on much of it. Persistent grey around the exhaust only seems to come off with something like Starbrite Color Restorer Polish.

 

[Poignard]

Problem is, the OP says he doesn't want to use oxalic acid, which is what I would use.

 

[johnalison]

Problem is, the OP says he doesn't want to use oxalic acid, which is what I would use.

I wouldn't use it as first choice but only for residual yellowing, which we haven't acquired in the last few years in local waters.

 

[38mess]

I bought a 5kg bag of Oxalic acid from a chemical company for £35. Mix with hot water in a 5 litre garden sprayer. Go around the hull twice. Does a great job and easier than brushing on a gel

Thanks, but I don't want to use oxalic.

 

[Poignard]

Thanks, but I don't want to use oxalic.

What you want or don't want is neither here nor there.

This is the YBW forum and you'll get not any peace until you do as you're told

 

[Aja]

Google informs me that the active ingredient of Grunt is phosphoric acid.

Amazon sells this stuff at a few pounds for 5 litres. Mix with wall paper paste as you would do with oxalic acid.

EVANS HI-PHOS High Active Concentrated Phosphoric Acid Toilet Cleaner and Descaler for Washrooms Toilet 5LTR Amazon.co.uk

 

[38mess]

Google informs me that the active ingredient of Grunt is phosphoric acid.

Amazon sells this stuff at a few pounds for 5 litres. Mix with wall paper paste as you would do with oxalic acid.

EVANS HI-PHOS High Active Concentrated Phosphoric Acid Toilet Cleaner and Descaler for Washrooms Toilet 5LTR Amazon.co.uk

Thanks, tried some similar stuff today which contains phosphoric acid, but it didn't shift the yellow stains.
I might have to use my oxalic after all.

 

[peteK]

A couple of years ago Amazon and ebay had loads of oxalic acid for sale,there is non on there now anyone know the reason.

 

[Poignard]

What's your objection to oxalic acid?

 

[38mess]

What's your objection to oxalic acid?

Apparently it takes a minute layer of the gel coat off which makes the hull act like a sponge and makes it harder to clean next time.

 

[Poignard]

After I have used the oxalix acid I wash the hull with one of those wash-and-wax products you can buy at a reasonable price in car accessory shops, or at a daylight robbery price in chandleries

 

[johnalison]

Apparently it takes a minute layer of the gel coat off which makes the hull act like a sponge and makes it harder to clean next time.

I see your point and have heard it before. I only know that the Yachticon ‘anti-glib’ that I have used has had no ill effect over many years. I don’t know if it contains oxalic acid but it has an acetic acid smell like Y10. It comes in handy bottles and is easier to use than Y10 even if it costs more than generic oxalic acid.

 

[Ribtecer]

Apparently it takes a minute layer of the gel coat off which makes the hull act like a sponge and makes it harder to clean next time.

I have a Rib, kept in a stack - no antifoul, with a bit of yellowing below the water line.

I cleaned it up with oxalic acid two years ago, it made a beautiful job and after a nice waxing it looked brand new. Also it had a bit of minor damage that I filled and fared.

After one night on a pontoon, yellow all back except where I had filled and fared the repair. I'm left wondering whether the whole hull needs a light rubbing down with a light grade wet and dry.

Be very interested in anyone's views/experiences.

 

[38mess]

Would that make things worse? I started off cleaning my white plastic hull with oxalic years ago, it did a beautiful job but left a Matt finish. A wax and polish brought it back to a lovely shine, but within a week the yellow stain had started to come back. If you use wet and dry to take the yellow off would it remove some gel coat?
Grunt is much kinder to the plastic but you have to pay for it

 

[Ribtecer]

Would that make things worse? I started off cleaning my white plastic hull with oxalic years ago, it did a beautiful job but left a Matt finish. A wax and polish brought it back to a lovely shine, but within a week the yellow stain had started to come back. If you use wet and dry to take the yellow off would it remove some gel coat?
Grunt is much kinder to the plastic but you have to pay for it

Well yes I think it would remove a tiny layer, but as with any form of oxidation caused by neglect, you have to get back to a new finish and then look after it with specialist polishes etc. thereafter. (Said neglect happened before I bought the Rib)

I seem to remember this process being referred to as "a mop and polish"

Again, any experts out there that can confirm would be very useful

 

[johnalison]

Would that make things worse? I started off cleaning my white plastic hull with oxalic years ago, it did a beautiful job but left a Matt finish. A wax and polish brought it back to a lovely shine, but within a week the yellow stain had started to come back. If you use wet and dry to take the yellow off would it remove some gel coat?
Grunt is much kinder to the plastic but you have to pay for it

Yellow stains can be a problem. I have only really had it on our years visiting the Baltic, though I think it was Dutch waters that were the cause. I can remember having to de-yellow and polish the hull mid-season once or twice, but haven’t used anything other than plain gelcoat cleaner for the last five years at home. I did hear from a friend that the advice given to him by a local professional was that eventually the yellow builds up so that cleaning becomes very temporary, and the best way of dealing with this is to use cellulose thinner to dissolve out the yellow and then start polishing from scratch. It did seem to work on his old Nic 32 but that’s all I know about it.

 

[arcot]

Apparently it takes a minute layer of the gel coat off which makes the hull act like a sponge and makes it harder to clean next time.

Likely kidney stones if absorbed through skin ...

 

[Bobc]

I use Starbrite hull cleaner and find it excellent. Also very good at cleaning the grip sections of the decks. Wipe on, wash off.