To epoxy or not to epoxy ...
Hi .. been away for a number of weeks due to massive work overload .. but, got my eye back on boats and sailign again now :)
I would have said (but i'm no expert) three coats of Blakes woodseal (UCP no longer available) as it really penetrates, leave for a week then epifaines, that was suggested to me by an ex merlin man who now builds the most beautiful wooden boats, the Spirit range.
Woodseal is good actually, but has no adhesive properties at all. SP Eposeal is the same. On a boat of this age you want two or three coats of SP 106 or 320. Put it on with a roller and heat it with a hair dryer as you go for maximum penetration.
Thats convinced me then SP 106/320 it is. I'll make extra extra sure I really have got a perfect sanded finish .. theres no second chances with epoxy. At some point in its life it had been "professionally refinished" .. by a guy whose final finishing was done with a rotary sander (no, not an orbital .. a rotary, as in angle grinder with a sanding disc) ... I'm busily removing some extremely visible semi-circular marks, and it already looks a lot better, even just wetted out with white spirit it looks oodles better than before.
So .. for a Merlin, roughly, how much 106 should I buy for 3 coats? this will be deck, side decks and transom, but probably not the hull internals this year, thats next winters project!
spray water on the floor when varnishing as this will keep the dust to an absolute bare minimum. I tend to use SP106 only becuase it is a lot cheaper than 320 i.e. 1kg tin of 106 about £23 compared to 320 £38 and does the same job. Be very careful using white spirit as the epoxy could very easily react!! Must use thinners or acetone when cleaning the surface.
yep, it will be degreased with acetone, the white spirit is just to wash out the paint stripper (methylene chloride).
Hi Robin... I have just coated my Spetember Girl in 2 coats of West Epoxy using the coating 207 Hardener (quite expensive)... I did all of hull and all of inside apart from under deck and on top of tank.... I started with a 6kg can and did a few repairs as well and still have about 1kg left so a 6kg seemed the best way to go and is significantly cheaper to buy in those quantities.... the best price I found was East Coat Fibre Glass Supplies up in Newcastle.... they were very helpful and supplied quickly.... she looks very pretty now!! Hope tht helps...
106 is cheaper, but remember it is not clear and nowhere near as UV resistant as 320. It's fine to use 106 for coating though, as the very slight colour change will be nothing compared with 25 years of sun bleaching just make sure it gets 5 coats of (Preferably) two pack varnish to protect it.
No one has mentioned sealing with G4 pond sealer before using Blakes Dura Gloss which is the route I have gone down for a number of boats and have found it to have worked well without it costing a fortune. CVRDA have discussed this at length.
My advice, go for a 3Kg pack of SP320 (dont buy it from a chandlery), degrease thoroughly with Solvent A, its not much more and doesnt leave any residue (acetone will if you believe SP tech support, they're quite helpful). Before coating go over with a hoover then a tack rag. Tiny bits of dust/grease will leave craters and ruin your day.
The ther trick with both is to wash the area being treated with hot, soapy water. This gets rid of the wax that the resin exudes (320 is particularly bad for this, especially if applied in less than ideal conditions). Acetone won't touch it, nor will the "proper" solvent unless you use gallons.
So, I managed to get two coats of SP on today, wet on tacky, and I measure it as roughly 600 microns, so theres enough of a coating to do the job.
i should add, this is not full-on fish eyes .. where the coating has avoided something in the surface .. just a sort of unevenness, like what you might expect from a paint roller
The resin was probably just starting to kick. When this happens it starts to go a bit like hair gel and ceases to level out properly. At 20 degrees C I would guess for fast hardener, mixed in something like a half pint plastic glass which has low surface area, that this starts to happen in less than 15 mins. If you have a fairly big area to do, its worth having someone else to mix for you in small batches. The quicker you get a freshly mixed pot down the better the finish.
Well, I dont fancy trying to do it again anytime soon, so, I'll flat it off with 240/320 grit wet and dry. I doubt I'll go through to the wood, its not deep, its just sort of mottled, and I have enough SP left to do another coat if I have to.
If you've used SP 106 you will want 5 coats for full UV protection. 106 is not as UV resistant as 320 and skimping on the varnish is a bad idea.
looks lovelly i'm about to start finishing 2717 decks having let the woodseal harden for 2 weeks, as i've got some 2pack blakes left from another job i thought 2 coats of that followed by 3 coats of ephaines one pot to build up the film
Lovely job Robin.
Thanks, its going better and better .. got a second coat of 2 pack PU on, looks great now :)
Robin, your fish eyes may have been dust contamination. After sanding I hoover extensively, then, just before coating go over the area with a tack rag (its a slightly sticky rag, I like the 3M tack pads best), this gets rid of the last few bits of dust.
Hmm, it was all wiped down with solvent, I dont think i was dust, but there again, what do I know, it wasnt working for me and it obviously does for other people.
Its always worth going over with a tack rag. You be surprised how much dust how much is on it. One spec of dust removed , one imperfection less. You can get oakey ones from b&q.
oh, and get some clamps on too.
I'll assume you meant microfibres insead of microballoons.
At last .. the final (almost) gluing operation on the centre board case ... just a couple of minor glue fills to do a little further back and an epoxy fillet along the front and its done ...
heh, OK .. I'll wait for further opinion on that one then. Bailing was never actually attempted, mostyl due to lack of a bucket. Transom flaps open bear away just resulted in a very slow progress.
Suppose it depends on how much wind there is - maybe keep your capsizes for a 3 and above haha. We tried bailing out (the boat)once and realised a steady flow coming from the CB case was gaining on us, but not till after about 5 minutes - how we laughed! After loosing a couple of b+q buckets in subsequent capsizes we stopped taking them and haven't missed having them.
Underwater transom is all very well if there is enough wind for you to speed away and use the flaps. But what if you capsize on a gentler day? It will happen!
It happens to us at Redditch all the time, you have no option other than to head for the beach!!
I think I remember someone having a 'sausage' shaped thing they put in the CB slot to slow the flow, but the low transom is an issue - we've had to get back to the shallows with the boat completely full more than once on light days.
I had the "overflowing centreboard scenario" in a Proctor IXb and found that a piece of small diameter pipe lagging stuffed in the top of the CB case stemmed the flow enough to let you bale out faster than the water coming in. I had it wrapped round the handle of the bucket.
You stemmed the flow in the CB case with your crotch once, Garry!
Have the same problem with Half Cut and found that we have to block the ingress through the centreboard case with something - a piece of pipe lagging or just the crew sitting with thigh jammed along it. Then you have to back the jib to sail anywhere and keep it backed to compensate for the extra weight and turning moment behind the mast. We managed to finish a race at Roadford once like this, mainly because the safety boat didn't come out to us so we had to cope by ourselves. They got a right slagging off when we got in!
When I started sailing it was usually the crew's T shirt that got stuffed into the centreboard slot....
back to the issue of epoxy - this return to winter is a complete nightmare as there is not enough warmth (even down on the sunny climes of the Hamble)to get the resin to cure properly. The boat is in the shed but that is not heated and therein lies the problem - for good epoxy work, control of the temperature is important.