PDA

View Full Version : epoxy on outside of strip boat only?



deltabrent
04-09-2010, 07:16 PM
Is it ok to do an epoxy coating on the outside of a strip built boat only?

The interior will probably be a sickens finish. red cedar strips on oak ribs. The boat is an inboard launch.

Stu Fyfe
04-09-2010, 07:24 PM
Polypropelyne or some other fabric will hold up much better in the long run.

Thorne
04-09-2010, 07:48 PM
No. The hull flexes, the epoxy cracks, water gets in, rot starts. If you need to epoxy a hull you need to glass it too.

What do the plans call for?

deltabrent
04-09-2010, 07:59 PM
this is a restoration.

I've replaced all the old ribs with Oak and can't really put a cloth down now inside over the ribs.

Epoxy would be OK if a glass cloth is used on the outside only?

I'm not really sure how old inboard launches and other larger strip built boats would have been covered? There isn't really any hint as to what was on the hull originally. Did they just paint it and let it swell?

paladin
04-09-2010, 08:49 PM
Make sure the inside is really clean and all sharp edges eased, then epoxy coat, at least twice, then a good coat of varnish is preferred over paint as paint won't let you keep an eye on the wood. Use a plastic fabric outside, not glass, preferably Xynole or Vectra as it will move with the wood.

deltabrent
04-09-2010, 09:10 PM
That sounds alright.

Any good links for more reading on the subject?

Any input on why not to us Sykens? I really like the idea of Sykens and have heard good stories about using it on decking etc.

paul oman
04-10-2010, 07:50 AM
I would use cloth/epoxy on at least one side (inside or outside) and perhaps a flexible epoxy paint on the other

johngsandusky
04-11-2010, 08:59 AM
I'm not really sure how old inboard launches and other larger strip built boats would have been covered? There isn't really any hint as to what was on the hull originally. Did they just paint it and let it swell?

Yes. Bass boats were built this way. My 39' ketch is 1.25" square strips on sawn frames. Only painted inside and out. At 42 years old she is so fair people think she is fiberglass.

bennieboat
04-11-2010, 09:46 AM
it is a heavy boat? thick strips? with a powerful engine?
the strips are fine, didn't need replacing?
then, what problem are you solving with glassing the outside?

i mean, the 'inboard launch' did fine for decennia now?
or are there trouble, leaking all season? or not structurally sound?
so, what are you trying to solve?

i guess, now, after you replaced all the ribs, the hull is sound and stable? the strips are fair, but show light through?
then, varnish her inside and out (inside for easy inspection, outside for looks)
or paint the outside, or you can tint the varnish dark, reddish or something, to obscure spots and repairs, or for looks
the varnish can be a flexible one, classic long spar varnish

my experience, with a 600 lbs sailing boat, strained from a tall rig, built from 3/4 inch nailed strips on oak frames, built in 1953

the boat leaked for a week, at the start of each season
then will only leak a little when sailing
but when my frames where rotten/broken, the boat leaked a lot
so a sailing day started with bailing, then was fine during the day
after repairs, the hull was sound again,
only varnish, and later bottom-paint on the underside
and some parts painted inside, but that was not helpfull

soon, i will put her in the water for the next season, and it will be an exiting and nerve testing week, then bailing, then sailing, i suppose

i guess i mean: you can glass her anytime, later, when you nEEd to

good fortune and enjoy,

Ben, Holland, Europe

deltabrent
04-11-2010, 05:19 PM
3/4" thick strips. Red Cedar.
Light does show through especially right on either side of the keelson.

There are a few missing strips and about 8 need to be replaced. The bow has had some bad repairs, and is pretty ugly. Most of the nails look pretty rusted through to pins. Also right at the base of the bow stem they have grafted in a piece of plywood on both sides as a fix to rotten and broken strips. It's not ideal but I don't know if it's possible to set right!? Or really worth it.

Maybe an epoxy based paint would suffice on the outside and varnish the inside.

It's mostly going to be a trailered boat so seasonal swelling won't really happen.

bennieboat
04-11-2010, 07:29 PM
the nails can hold on without their heads (mine do)
you will know when you try to replace some strips

i wouldn't bother with the modern two part paints
these are unforgiving and hard to repair
but more important: rigid modern paints crack between strips, especially along the light showing lines
when you glass the hull, these paints are fine

ah, and don't try to fill the light showing lines, that will prevent swelling them thight, causing leaks

may be varnish her inside and out for now and enjoy her in the water (with some bailing)
next year, repair the bow (it shouldn't be ugly)
and later, when you need to, go glass the hull, outside only
(i am glad i did, but would hesitate to do it again, for al the hard work, and the stress)

enjoy,

Ben

Stu Fyfe
04-11-2010, 08:12 PM
I've used the two part epoxy paints on my fir strip plank with polyproplyene and epoxy. It's held up nicely for twenty eight years. I recoated three times.

Larks
04-11-2010, 09:19 PM
3/4" thick strips. Red Cedar.
Light does show through especially right on either side of the keelson.

There are a few missing strips and about 8 need to be replaced. The bow has had some bad repairs, and is pretty ugly. Most of the nails look pretty rusted through to pins. Also right at the base of the bow stem they have grafted in a piece of plywood on both sides as a fix to rotten and broken strips. It's not ideal but I don't know if it's possible to set right!? Or really worth it.

Maybe an epoxy based paint would suffice on the outside and varnish the inside.

It's mostly going to be a trailered boat so seasonal swelling won't really happen.

Can you post a few photos so that guys here know what they are advising on? The fix for a trailered boat will be quite different to one living in the water. For example my Hartley TS 16, which lives on a trailer, is glassed externally and only painted internally.

There may also be varying repair options for the keelson gaps.

Falcon500
04-11-2010, 09:44 PM
huh, the deck on my boat cracked after one year near the centerline, and my planks are moving under the fiberglass in the hull, so im going to say %$*K fiberglass and rebuild it carvel :)

deltabrent
04-12-2010, 02:23 AM
I think some for of fiberglass or similar cloth and epoxy on the outside and a solid paint on the inside would sound good.

So everyone says no to Sykens inside?

bennieboat
04-12-2010, 05:15 AM
your resume sounds okay, without knowing your boat (not even a photo?)

but for the Sikkens (spelling?) inside, can you be more specific?

Ben

deltabrent
04-12-2010, 02:40 PM
OK It's spelled Sikkens. My Dad is convinced we should just coat the whole inside with a bunch of coats of SRD Sikkens Cetol. He uses it on his commercial fish boat deck and said it will be fine for the interior.

I'll have to get my act together and post some photos.

l.clayton.parker
04-12-2010, 03:02 PM
I have used Sikkens in the construction industry. As a weather resistant finish it is hard to beat. It is an alkyd oil based coating and should work well, but I have never heard of anyone using it on a boat before so don't take my word for it.

bennieboat
04-12-2010, 03:46 PM
'interior' that can be a lot of different things
furniture? hull structure? floor boards?
and 'hull structure' is different, when on a trailer, submerged for the season, dry inside or not...

i am not familiar with the Sikkens Cetol products
(there are several, with different indications, like TGX, SRD, and tinted/ not tinted)
i think i know, that you can't remove it with chemicals, and you can't brush it on, and application marks will show (will not flow?)

but i know: even if you 'glass' the hull, don't glass/epoxy the parts you will walk on, not on deck, and not on floorboards etc
it will damage, and let water in, and is not easy to touch up.
(well, it is not a law, or a rule, and there might be applications for that, but i wouldn't glass decks on my boat)

now you mention it, i will consider cetol on some parts that get abused in my boat, see for myself, learn

side note to self:
here, we say 'sikkens' as in the English 'sick' , so: 'sickens'
i realise, that English speakers say 'sikkens' as in 'psychic', so: 'sykens'? is that so?

Ben, Holland, Europe

deltabrent
04-12-2010, 07:12 PM
He's put sikkens on the whole deck of a 41' commercial fish boat. Says he loves it and it's cheap.

I'd do it to the inside of the planking and ribs. I'd probably have bright finished floor boards, seats and cap rail around that. Deck would probably be mahogany plywood bright.