New Boat Antifouling - Thoughts?

ramio · April 14, 2009, 19:34:21 CET

Skip,

Take care when you apply the osmosis treatment directly on the gelcoat. I have reason to think that unless a water base primer is applied, the gelsield 2000 may react with the gelcoat and give you problems after.

As Shanook mentioned higher up, like him I launched the boat with the Delta rosso osmosis treatment, after a couple of years I noticed 4-5mm blisters apearing around the waterline. These eventually formed on all the underwater surface. Like Shanook, I painstacingly scraped and sanded all the way to the gelcoat (and it wasn't easy). We had an argument with the manufacturer of the treatment, but to no avail. In the end we went for the gelshield 2000 treatment aplied as you said.
Last couple of years I noticed the blisters returning, this year they are all over. It was recomanded that the 2 layers of water based primer be applied before the osmoses treatment to serve as a barier and prevent the tinners in the treatment reacting with the gelcoat.

That's as far as I know. Will see what I'm doing about it next year. This year boat in the water as is. Would be happy if anybody got some info to share on the problem.

skip · April 14, 2009, 21:03:37 CET

Ramio I'm not expert by any stretch of the imagination, I spoke with International before commencing the treatment, sanded down the hull, wiped it down with their special cleaner and then commenced with the Gelshield coats.

Given your experience one possible explanation is that your hull already had osmosis in it before you started and no matter how many barrier coats you apply it's already there.

If you're going to have to restrip I would seriously try and get a professional to inspect your hull before you repeat this all over again. The West Systems document I attached with Gaffer's post about compromised water barrier details how to check and repair existing blisters etc.

Who makes the water based primer?

shanook · April 14, 2009, 21:21:08 CET

Nick i told ramio about the water base primer. If I am right I started by applying a water base treatment before the gelshield.
I Stand to be corrected as I did this about 4 years ago. Just a thought, it might have been a water base antifoulfing not to react with the gelshield. As i said I stand to be corrected. But the guys at internationa know best what can be done to protect the boat.

skip · April 14, 2009, 21:45:06 CET

What do you reckon about the remote possibily of their already having been osmosis/small water blisters before Ramio started.

Might be a good question to ask International http://www.yachtpaint.com/UK/feedback/feedback.asp

I used their feedback form and put the enquiry as Technical Enquiry and got very helpful answers from Richard Jerram the UK technical manager.

I think in Ramio's case after removing all existing paints, primers and gelshield (recommend soda blasting), and then after ensuring the hull is thoroughly washed and dried, he will need to treat any existing osmosis by applying Gelshield plus first after having totally removed the gelcoat in the affected areas.

Have a look at these:

http://www.yachtpaint.com/UK/boat_painting_guide/pdf/fibreglass/treat.pdf
http://www.yachtpaint.com/UK/boat_painting_guide/pdf/fibreglass/protect.pdf

Gelshield Plus Product Info
https://secure.international-coatings.com/pds/yacht/GB_ISO_M_5000292.htm

They also now have Epiglass HT9000 which seems to be Epoxy Glass that can be applied directly to the gelcoat as further protection before Gelshield 200

bahri · April 14, 2009, 22:50:07 CET

Quote from: shanook on April 14, 2009, 17:22:19 CET
bahri if your boat is still on gel coat than its not just anti fouling that u need to do but a water proof barrier first.

Yes thanks for that.

I will need to apply the waterproofing gel before the antifouling.

Unfortunately I am not able to perform all this myself dues due to physical constraints (!) - are you aware of a company who offers this service?

thanks .

skip · April 14, 2009, 22:59:02 CET

I think various boatyards will do it for sure. You could try Charlie at Tecnomarine 21 570250

ramio · April 15, 2009, 06:52:35 CET

Skip,

I don't think its an osmosis problem from the start, as the blisters mainly are from on top of the gelcoat. Where the gelcoat came off is because of a different problem. I think I have a defective gelcoat layer. This mainly to problematic materials that were about during the time of my boat being manufactured. I think gelcoat is too brittle as hairlines are visible on all areas. This doesn't cover the problem why the blisters showed from the 1st year. to that point only the osmosis treatment blistered up. Apart from that, the water content and foul smell usualliy present inside the blister with osmosis were not present. The blisters I have are dry even when boat had just come out of the water.
To me this represents build up of presure by some gas, produced with a chemical reaction. The osmosis treatment is doing its job as under it is all dry.
Will have to seek advise on this. Anyway this has to be treated next year, I'm not ruining this year's fishing...hell with the boat.

shanook · April 15, 2009, 09:35:02 CET

Ramio is right i think either the material was defective or else the first treatment applied to the boat caused a reaction making the gelcoat brittle. Its not an osmosis matter as none of the telltale signs are present. there are hairline cracks elsewhere so the probability is that the material was defective in the first place. its nothing that cannot be set right its a hussle to have to do it thats all....grrrrrrrrr

skip · April 15, 2009, 12:38:41 CET

Interesting update. Perhaps would warrant removing the gelcoat from the bottom and rebuilding it up with something like Gelshield Plus and any fillers as required.

The removal would be well suited to Sandblasting as you would want to remove the gelcoast especially if you feel it might be compromised.

ramio · April 15, 2009, 19:10:15 CET

Was thinking of applying layers of west system directly to hull once the gelcoat is removed. But will have to seek more advise first.
Problem is next year I will be short of both time and money, as am planing to move into the new apartment that is under way.So!!!!!!!

bahri · April 16, 2009, 13:58:06 CET

Quote from: skip on April 14, 2009, 22:59:02 CET
I think various boatyards will do it for sure. You could try Charlie at Tecnomarine 21 570250

cheers ... will do.

skip · April 16, 2009, 18:02:15 CET

One thing to add, no matter who it is/which yard all supervise such works. I don't like leaving things especially below the water line to someone without me being around.

shanook · April 16, 2009, 18:48:51 CET

bahri your boat is 14feet no! so why dont u do it urself if u are able to?

Destination Sea · April 17, 2009, 23:04:41 CET

Bahri kont ghamilt id dghajsa li kelli jien xejn ta barra min hawn naqra pacezja.
ahsel sew il qieh, minbaghad xkatla hafifa hafna b xi sandpaper 400 (qiesek qed ixxejjer)
msaghha w tija tlett passati osmosis prevention skond l instructions (twinpacK) w wara 2 antifouling. jien nuza l attiva (minghand charlie ta riniker tecnomarine) w sibta tajba .kien qalli bija siehbi.

bahri · April 17, 2009, 23:26:22 CET

ma nafx kont qed naqta qalbi ghax siehbi qalli tghidx kemm hu difficli taghmel il kolla qabel l-antifouling!