Pressure wash GRP?

[muckypup]

Will pressure washing GRP damage it? Parts of Harlequin (the roof) have a non-slip wobbly finish which is difficult to clean.

S.

 

[Hoolie]

Can do. I used to pressure wash our non-slip areas until I noticed tiny bits where the gelcoat was chipped off. I don't do it now except on a low-pressure wide-spray setting /forums/images/graemlins/frown.gif

 

[savageseadog]

I have pressure washed in the past but was advised by a surveyor not to, as it can blow out the sealer.

 

[Hardley]

Don't do it, it will blast tiny pin prick holes where the gelcoat is thin.
you could use Oxyalic Acid but be very careful with it and wash off with running water.
I would go to the nearest caravan shop, they sell a cleaning paste that I found very good.

 

[Gothik29]

As per the above advice - I'd recommend you don't pressure wash gel coat. I've heard too many stories about damage to gel coat. I use a good scrubbing brush and Silky - available from most caravan shops at a very reasonable price.

 

[savageseadog]

Use Lidl Bathroom cleaner it's ex

 

[Guest]

Yards have been pressure washing boats for years ..... top and under.

I've been pressure washing all my boats ... albeit cheapo DIY machines - but still high pressure.

As to what I do .. first a good blow over with PW ... then a good rub with Cillit Bang Lime and Rust Bog cleaner ... wash off ... and a good PW again to remove all traces of Cillit.

This year I didn't finish of as I should have done .. that is with a good polish to keep the gel smooth and stuff not stick to it .. so this year I have ended up with mucky topsides again.

So when I lift out ... which due to engine in bits - will probably be in couple of weeks - my Bosch PW will be dragged out and she'll get blasted as usual.

Of course though - my boat and previous are built like battle tanks - old MAB's ... built like out-houses !

 

[Avocet]

Speaking as someone with a 1972 boat whose gelcoat is on its last legs, I think I'd be quite cautious about using a good pressure washer on my decks. I too have the moulded-in non-slip bits and they are really just pure gelcoat because the fibres can't follow the fine corrugations of the non-slip pattern. I have used one before but as soon as there is the slightest weakness in the top skin, it can flick a little piece of gel off and then the water goes down into the laminate - after which, the problem only ever gets worse!

 

[muckypup]

hmm... I think I will have to stick manual labour. I have found that vim (or is it cif now?) works well, but is a lot of work.

S.

 

[Guest]

I'm lucky you see ... painted non-slip ... and to be honest it needs blasting off !!

Oh and to ingress of water into where gel has chipped of ... why do people think that a pressure washer will put wtaer in that normal exposure wont over time ? In fact water is able to get in whether under pressure or not ... exposed fibres will wick the water in as fast as a rabbit gets .......

The only reason IMHO that a PW is not to be used is if you do have gel that will be driven of by the jet ... otherwise its clean it up Jim !!

 

[Saddletramp]

I was told that CIF etc can leave a residue, amoonia I think, that can get into the gel coat. I think you have to take a view on these things. As long as you don't do it all the time it is probably okay.

 

[Guest]

Most cleaners that work have something like ammonia in them or a base similar.

If not ammonia then it's an acid base such as Citric / Oxalic etc.

Like many things in life - if taken to extreme - they all harm whatever they touch. The trick is use sensibly and wash off properly.

 

[muckypup]

I can't wait until the future when you will be able to buy a little robot that carefully cleans your boat when you are not there... /forums/images/graemlins/smile.gif

 

[Guest]

You can already buy a system that keeps your boat effectively out of the marinas water by "bagging" it alongside ... developed for those boats that sit alongside waiting for owners to remember they have a boat !!

 

[Avocet]

I wasn't saying that the pressure washer forces water into the laminate DURING the pressure washing operation! (Although it might well force a little bit in)! What I said was that AFTER the little bit of gelcoat has been knocked off, water will get in. What I probably should have added was ..."over time, by any means it can"...

 

[Guest]

fair enuff ... /forums/images/graemlins/wink.gif

 

[Hardley]

Yes Silky is the stuff, could not recall the name, cheap and good.