single
New member
I have just painted some marine ply with epoxy resin.It looks amazing but why don't people use it on handrails,rubbing strips etc. I'm sure there is a simple reason?
Epoxy on wood
- Thread starter single
- Start date
GrahamP
Member
Lack of UV resistance
prv
Well-known member
It breaks down in UV (ie, sunlight).
Some people do use it for strength and waterproofing, overcoated with UV-resistant varnish.
Pete
Poignard
Well-known member
Five reasons I don't use it :
1. it degrades in sunlight
2. it's a very good moisture barrier, ie it's good at keeping moisture out but unfortunately it's also good at keeping it in! So when it gets chipped or cracked, moisture creeps in under it and rot can start
3. it's a nuisance having to mix up two components
4. it starts to go off too quickly
5. it's expensive.
single
New member
I suppose 1&2 are the main reasons then.I just used it to seal a gas locker ready for normal paint.
Poignard
Well-known member
Even there it is best to coat each piece of timber individually before assembly. If you paint it over joints in tmber it will crack if/when the joint moves.
pmagowan
Well-known member
I think this is one of the main reasons. It is not able to expand and contract with the wood and thus you get cracks. Once the water gets in it is very difficult to get the epoxy off to repair. It is not a good replacement for varnish but many 'wooden' boats are coated in it on the hull with glass fibre mesh to reinforce. I think this may give the best of both worlds as you overpaint it thus giving the UV protection and it keeps the wood dry.
PhillM
Well-known member
Isn't that "sheathing" the hull. from everything I've read thats only good to help a dead boat to live its final few years. As the wood moves the epoxy and Gf doesnt, leaving gaps that water in and eventually the wood rots.
Daydream believer
Well-known member
No . Not quite true
I sheathed a clinker yacht with epoxy & 300 gram matt but I also soaked the inside of the hull with a special resin that soaked into the wood. All supplied by wessex resins. Current owner ( 14 years later) reports all OK & no problems
There are brand new yachts built using the West system. There is one in Bradwell marina that was designed by Stephen Jones & built a few years ago- Looks gorgeous
NealB
Well-known member
Sheathing a wooden/ strip hull is pretty common as a new build technique.
Here's just one, of many examples:
http://www.fairlieyachts.com/fairlie-55/
PhillM
Well-known member
Gentlemen, I stand corrected.
Poignard
Well-known member
And a barque - t/s Tenacious
Daydream believer
Well-known member
I think Stephen Jones could show them how to design a yacht!!!!
NealB
Well-known member
Top marks for thread drift, there...but, yes, I'm inclined to agree with you!!
Tranona
Well-known member
No, don't feel you have got it wrong! There is a world of difference between boats designed to be built from wood/epoxy composites such as those mentioned by others and sheathing an existing wooden boat built in a traditional way. The former is indeed a good method of construction, but the latter is usually a disaster.
Rigger Mortice
N/A
I used epoxy followed by polyurethane on my tiller and it looked fantastic for a while. Unfortunately, as others have said, water got under the epoxy and it had nowhere to escape to. I ended up sanding the whole lot off and now just use polyurethane on its own.
oldsaltoz
New member
+ 1.
oldsaltoz
New member
I coated the saloon table with epoxy (3 coats) after leaving it in sun for a fey hours to warm it up, applied the epoxy wet on tacky to avoid sanding between coats.
Then applied 5 coats of high UV resistant vernish (5 coats)
That was 5+ years ago and it still looks like I did it last month.
I suspect the epoxy hardens the timber surface thus making a lot harder to damage.
By the way, if you plan on painting over an epoxy you MUST first apply and epoxy primer, failure to do this will mean any paint will chip off very easily.
Good luck and fair winds.
Then applied 5 coats of high UV resistant vernish (5 coats)
That was 5+ years ago and it still looks like I did it last month.
I suspect the epoxy hardens the timber surface thus making a lot harder to damage.
By the way, if you plan on painting over an epoxy you MUST first apply and epoxy primer, failure to do this will mean any paint will chip off very easily.
Good luck and fair winds.
oldsaltoz
New member
I coated the saloon table with epoxy (3 coats) after leaving it in sun for a fey hours to warm it up, applied the epoxy wet on tacky to avoid sanding between coats.
Then applied 5 coats of high UV resistant vernish (5 coats)
That was 5+ years ago and it still looks like I did it last month.
I suspect the epoxy hardens the timber surface thus making a lot harder to damage.
By the way, if you plan on painting over an epoxy you MUST first apply and epoxy primer, failure to do this will mean any paint will chip off very easily.
Good luck and fair winds.
Then applied 5 coats of high UV resistant vernish (5 coats)
That was 5+ years ago and it still looks like I did it last month.
I suspect the epoxy hardens the timber surface thus making a lot harder to damage.
By the way, if you plan on painting over an epoxy you MUST first apply and epoxy primer, failure to do this will mean any paint will chip off very easily.
Good luck and fair winds.
Daydream believer
Well-known member
Like most things there is a right way & a wrong way. i had to put a lot of work into the boat that I sheathed & I am convinced it has given a an old boat years of service.
It started with stripping to a bare hull, , removing decks & just leaving one bulkhead & some deck beams,sandblasting to remove old paint inside & out, reducing moisture content to between 12-14% repairing the broken ribs,re gluing the lands, resin treating all the inside & then sheathing the outside then rebuilding the rest of the boat. All done in factory conditions
It would have been a waste of time just to stick a bit of resin & mat on a wet hull & expecting it to work
