Damp proofing.

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trebor
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Damp proofing.

Post by trebor »

Anyone tried using a damp proofing liquid inside a grp hull.
I am thinking a thoroughly dried out hull, then pour Thompsons or somethng similar, hopefully any water accidentlly or otherwise that gets inside hull will not be absorbed.
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Rupert
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Re: Damp proofing.

Post by Rupert »

How well would it stick to the GRP?
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trebor
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Re: Damp proofing.

Post by trebor »

Pass.
The Water can be absorbed so I just assumed the thinners' water proofer is suspended in would be smaller molecularly
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Michael Brigg
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Re: Damp proofing.

Post by Michael Brigg »

trebor wrote:Pass.
The Water can be absorbed so I just assumed the thinners' water proofer is suspended in would be smaller molecularly
A damp proofing agent needs to impregnate the target surface. Molecular size (as they say) doesn't matter! Well at any rate, its not everything. On fabric this then allows the fabric to shed the water before it has a chance to soak into the porous surface.This is really the critical issue. The damp proofer only really works if the surface is porous. On a non porous surface, it isn't really needed, or wont work anyway as it wont stick. On glass fibre or resin, the water soaks in because the surfaces support a capillary action, (a property that is caused by the physical chemisty and shape of the water molecule, which in turn allows the liquid to have a "surface tension."

Think of the difference if you mix sawdust or sand with your damp proof product. One will absorb the Damp proof but will turn to mush anyway if the water cant drain off it, the other will become an unuseable mess. In the wrong place niether will be of benefit.

Unless you are working with ferroconcrete.

I think damp proof agents would work for a short while but would then make the (tals: Edit :-tanks) or other parts very messy and (Edit: will also be) impossible to remove. Best sealant would be Bilge paint, and an inpection hatch big enough to use a sponge, or a bung hole in the sump ogf the tank. (Ed with his knowledge of oil sludge and Cinquecento engines knows far mor about this than I do.
Last edited by Michael Brigg on Fri Oct 02, 2015 5:47 pm, edited 1 time in total.
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Ed
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Re: Damp proofing.

Post by Ed »

I have considered this in the past.

Even bought 5 litres of Thompsons sealer, but afraid never actually got enough courage up to actually use it....or found the right place/time to do so.

So if you try it, do report back.

cheers

eib
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