Petrol/gasoline/ethanol

I have been plagued by a grp tank issue for a while. I replaced gaskets and hoses but still get water in my grp in built tank. Layup is a derakane resin and resisting the fuel very well, but has a hole I have disovered in the roof.

I've asked around local suppliers and have only found two resins that the manufacturer is willing to state they are petrol safe. Despite the searching on this site I am still confused if either will fit the bill.

5kg Vinylester Resin (Atlac 580) http://www.cfsnet.co.uk/acatalog/5kg-Vinylester-Resin--Atlac-580--RVE580_005.html#SID=252

EP 575 https://www.alchemie.com/epoxy-resin/laminating-resin/4840.html

Both are confident in their product. I wonder if anyone has any experience or could explain the chemical resistance tables to me please.

 

I have found out the first resin is bisphenol A vinyl ester urethane resin.

The second a novolac epoxy. I will use this one to repair

 

I have no experience with their product, but I do have experience with GRP gasoline tanks leaking. I would replace it completely if possible with a metal or rotomolded plastic tank.

You said; "grp in built tank." Does this mean the tank is integral to the hull, or is it freestanding? In the US Canada and the EU integral gasoline tanks are not permitted because of the danger of a hull puncture releasing gasoline.

 

I'd be very surprised if the tank was integral to the hull, for the reasons you've mentioned Peter. I too would recommend replacement though any of the major epoxy formulators and the discount formulators, will have an appropriate goo. Most of the usual formulations are very resistant to petrochemicals in general.

 

I'm sure you're right PAR. But replacement is a better solution. It will last far longer and eliminate the problem. On an older boat the new tank will outlive the boat.

 

Agreed and most professionals will likely insist, if only for liability issues. Tanks are cheap and come in about every shape and size, so . . .

 

Thanks all for replies. The boat was built in 2001/2 and at the time the manufactur used the hull as one side of the tank. Only in the last two years have they changed this to stainless tanks being bedded in to the hull due to changes in uk regs. Summer is upon me so I was after a quick fix, and a new tank will most likely be done in winter. I have fitted an external tank but would still like to repair internal tank to stop accumulation of water, and keep it as it was made if possible.

 

If you keep the tank as built, with one side of the tank being the hull, you will probably be in violation of the Recreational Craft Directive (RCD). I am not aware of how that would be enforced but there must be some mechanism for that. You might want to check the Recreational Craft Directive https://www.rya.org.uk/SiteCollecti...ents/RCD Documents/1 RCD Compliance Guide.pdf

 

I am not an rcd expert but I thought that was for new builds. Probably why the manufacturer changed tank design, however they must have made 200+ boats with a built in tank, if rcd had to be retrospectively fitted to all boats that no longer meet requirements that would have a massive impact on the whole 2nd hand market.

If the boat coaded for passenger service it might be an issue.

I like the plastic tanks in the US but the postage is usually crazy

 

As you said, I am not an expert in the RCD. Yes, the postage would be huge. Are they not available in the UK?