Hull back to bare GRP - VC Tar 2 and antifoul.. or what??

[Ben998]

Hi All,
We spent the nicest weekend of the year so far scraping the old antifoul from the hull. Lovely job. Next time I am paying someone to do it !! . Anyway, its nearly done now and should be finished with another half days effort - stripped and sanded ready for the new antifoul.
Ive been advised to VC Tar 2 it and then antifoul. The hull is very dry for a 10 year old boat ( very very negligable moisture reading ) with no signs of osmotic blisters and is in very good condition.
Is it worth applying VC Tar 2 / Gelshield 200 or other osmotic prevention treatment as obviously they arent going to stop osmosis from happening but may help delay the onset if and when it were to happen?

cheers,
Ben

 

[Guest]

Just done that, somewhere round ten layers of antifouling, took ages.
Under the antifoul there was a primer, and no blisters anywhere, 1980 boat.

I have primed again with two coats of International Primocon

This was recommended by both the surveyor and a local professional boat painter.

Iron keel treated with a phosphoric etch, primed and faired with International Watertite, then two more coats of Primocon.

Looks like a new boat.

 

[Mudplugger]

If you have expended the effort to get the hull back to its pristine glory, then in my humble opinion it is well worth the additional effort to put on 2/3 coats of VC tar Epoxy followed by a couple of coats of VC Offshore..Been there ,done that, and had a 22year old Hull with no signs of the dreaded lurgy, and the benefit that if you need to take of the a/f next time you will find that its much easier to get down to the Epoxy. Brilliant treatment in my HO. It is great for the peace of mind!!

 

[Gin]

If the hull is dry after 20+ years and you are going to treat it in the same way as previous owners( 5 months out of water each winter?) then one argument is why go to the time and expense.

However, if like me, you wouldn't want to risk the expense of dealing with an increasingly wet hull sometime down the line, then why not put on an epoxy layer as a belt and braces measure. The cost now would be relatively low and the hull is probably,from what you say, dry enough not to be locking in to the substrate a quantity of water which cannot escape when overwintering.

Also when it comes time to sell the magic words "hull epoxied" will do wonders to encourage potential buyers to make further enquiries, as they will be trying their best to avoid a wet hull and the attendant costs of dealing with same.

So for my money, the answer is yes if you can afford it, do it!

 

[Talbot]

VC Tar 2 - easy to put on and provides a very smooth finish (removing any over-enthusiastic angle grinder burrs) needs at least 5 coats and a good drying period, but the result is much better at coping with an occasional ding.

Gelshield - a very impermeable layer, but needs to be done very carefully with absolute obeying the instructions. A ding can crack the layer rendering it useless.

Full epoxy treatment - obviously the best but needs to be for the price!

I used VC Tar 10 years ago!

 

[KREW2]

Hi
Not wishing to be pessimistic but if a boat has been in the water for a few years it will have absorbed a nominal amount of moisture I was told epoxing should only be done as prevetative measure on a new hull. Epoxying over existing gel coat on a boat that has been immersed for a few years can entrap any moisture causing water retention and not allowing the hull to dry out as well when on a winter layup. This advice was given to me from a surveyor in New Zealand and my local boatyard has told me he agrees with that theory, however I'm sure there are lots of people who have different notions.
regards KW

 

[Ben998]

Hi,
Its been out of the water for 18 months and is probably as dry as its going to get without baking it under UV lamps. I couldnt see any problems with the gelcoat where we have stripped it back.
cheers,
Ben

 

[Phoenix of Hamble]

Ben,

When you say back to bare GRP... do you mean back to the glass, or back to the gelcoat?

 

[Ben998]

Sorry, back to the gelcoat.

 

[Birdseye]

If it really is dry after 18 months out, then you dont yet have osmosis. So its best to prevent it happening by coating. Tar epoxy used to be the most waterproof coating you could get but that was when it was made by the old NCB at their chemical plant in Orgreave. Personally I would now go for a non solvent epoxy from some major name.

Would be worth having on record a letter from your surveyor giving the moisture readings before coating - there is a good argument that coating a damp boat after 20 years is not sensible. So any future buyer might want re-assurance that the boat really is dry and since you have the moisture readings anyway.........................