Epoxy wood before re-varnishing?

[Tim Good]

I read in an old PBO this:

"the answer avoiding porous varnish to to use modern epoxy resins. Once the wood is prepared then instead of using a thinned coat or varnish first, apply three coats of epoxy as base instead. Ensure you then use a compatible varnish that wont react with epoxy"

A bit OTT for a restoration of a cockpit table or probably a good idea considering it will be outside all the time?

 

[pmagowan]

Probably a good idea. I am going to be revarnishing my brightwork this winter after replacing the deck and superstructure. I was thinking of doing up a number of test panels to see which way works best for when I come to build my new boat. The benefit of the epoxy is that the wood is sealed and protected and the varnish has a perfect surface to stick to. The potential downside is that if it gets damaged then it is a lot harder to get off to repair. Some boats have their topsides encapsulated with glear glass reinforced epoxy which is then varnished. The bond between the epoxy and wood does seem to last a lot longer than varnish alone. You do have to take into acount that if the wood is not completely sealed then it will be able to expand and contract and the epoxy might not be able to allow for that so you can't simply paint one surface of a large area of wood.

 

[Tranona]

Have done both over the years and not convinced that epoxy is the answer - at least not the normal epoxies widely used here. There are water based epoxies that claim to be better as foundations for varnish but they require a lot of work and good conditions. I have just been stripping some mahogany part of which had epoxy. Even though the epoxy has suffered from partial decomposition from UV, it is almost impossible to remove cleanly and leaves the underlying surface patchy.

I am a firm believer in the latest type of woodstains for durability, ease of application and low cost for outside work. Three coats, one a day with no rubbing down in between and it flows easily to give a good finish. You can reasonably expect a life of 5 years without any attention.

There is an article in the latest PBO on using epoxy for coating - well worth a read.

 

[Tim Good]

I am a firm believer in the latest type of woodstains for durability, ease of application and low cost for outside work.

And varnish over the top or just the woodstains?

 

[johnalison]

I had a lot of trouble with the washboards on our old Sadler. The varnish would get damaged where they met and the wood would discolour. I solved it by coating with epoxy glue and varnishing over, so I imagine that epoxy could be used more widely, with varnish, of course.

 

[pmagowan]

And varnish over the top or just the woodstains?

For some reason some people like just woodstain as a finish. There is no accounting for taste

 

[Tradewinds]

Javelin, who works at Harbour Marine Services, Southwold offered this varnishing tip a while ago

http://www.ybw.com/forums/showthread.php?361701-Varnishing-tip&highlight=varnishing

 

[MikeBz]

I've used a clear penetrating epoxy sealer (CPES) on bare wood followed by 2-pack varnish with excellent results - super finish and extremely durable. Keep putting the CPES on until no more soaks in, then put the first coat of 2-pack on before the epoxy has completely cured and you get a chemical bond between the two. Not the cheapest solution but pays for itself in the longer term.

 

[Tranona]

For some reason some people like just woodstain as a finish. There is no accounting for taste

You clearly have no idea what you are talking about. Suggest you do some research into the woodstains I am referring to before making comments.

A good starting point is the extensive trials carried out by Richard Hares, a timber technologist. that have been widely published over the last 10 years in both Classic Boat and PBO.

 

[lw395]

A lot of things sold as 'woodstain' are a brown muddy gunge, which might look OK from a distance, or on a fence, where the object is to have a uniform colour of wood and have the wood last OK with low effort.
Some of them might be a bit better, the worst ones look like an accident involving oxtail soup.

If you want a deep, clear gloss, where you can see the grain of good wood, then you are going to have to work harder.
Proper coating epoxy followed by two pack polyurethane is probably the best tough finish you will get.
I had a dinghy varnished thus, I kept it indoors.

 

[Fantasie 19]

You clearly have no idea what you are talking about. Suggest you do some research into the woodstains I am referring to before making comments.

A good starting point is the extensive trials carried out by Richard Hares, a timber technologist. that have been widely published over the last 10 years in both Classic Boat and PBO.

Tranona - what's your recommended woodstain?? I have some woodwork to do this winter and I'm not interested in 45 coats of varnish with finer and finer rub downs between coats..

 

[oldsaltoz]

I absolutely hate maintenance, and particularly maintaining timber on a boat and have spent many years devising ways or replacing the stuff, I'd rather be sailing thanks.

Any timber left on the boat now has been sanded down washed with Acetone the coated with 3 layers of epoxy resin making sure that every nook and cranny is fully sealed and well coated, then sanded and wiped with more acetone just prior to to adding the varnish, usually 5 coats.

The trick is to use only High UV rated resins.

Good luck and fair winds.

 

[Mel]

I have used a product called "SP Eposeal 300" for a few years now. This is a very thin clear epoxy primer that soaks into the wood, it dries very quickly but can be used once mixed over several hours so long as it is kept in a jar with a top on. I apply several coats of this epoxy primer and then I finish off with several layers of yacht varnish.

 

[pmagowan]

You clearly have no idea what you are talking about. Suggest you do some research into the woodstains I am referring to before making comments.

A good starting point is the extensive trials carried out by Richard Hares, a timber technologist. that have been widely published over the last 10 years in both Classic Boat and PBO.

As I said, there is no accounting for taste.

 

[davidpbo]

I have some mahogany boarding steps to varnish.I have varnish and epoxy and no desire to increase the number of unctions in the garage.

What do I thin the (West) epoxy with (I have acetone) and to what proportion please?

 

[TimBennet]

I have some mahogany boarding steps to varnish.I have varnish and epoxy and no desire to increase the number of unctions in the garage.

What do I thin the (West) epoxy with (I have acetone) and to what proportion please?

You never thin West Epoxy. There's loads on their website and on the Epoxyworks website telling you why.

The only acceptable way of reducing the viscosity of West epoxy is by warming it slightly. Work in a nice warm place (20°C) but don't heat the epoxy itself beyond this. But you can warm the work piece further. Put your steps in a boxed off area and get the wood a fair bit warmer. Then remove the heat and epoxy coat the steps as their temperature falls. The falling temperature will help draw the epoxy into the wood (slightly) and prevent out gassing.

Then over coat with several layers of good single or two pot, polyurethane UV varnish. Finally buff with a non silicone polish and they will look good.

Woodskin is a good finish and if you like that finish, it is a way to go. But if you want a varnish finish, then sadly varnish is the only way to go.

Personally I wouldn't bother with epoxy-ing anything that didn't need enhanced water proofing. For instance it makes sense with a plywood dinghy, but boarding steps? Not sure.

I would either go with the two pack clear primer and then either single or two pack varnish, or my instinct would be to go with traditional single pack varnish and store the steps out of the sun and benefit from the ease of touching them up when they get the odd knock when handling and using them.

 

[oldsaltoz]

Rather than thinning you can and should use heat. Simply stand the resin in a pot of warm water and put the items to be coated in the sun or heat them by other means, the Epoxy will flow freely into the timber, it's also a good practice to wipe the timber with Acetone just before coating, this helps / ensures no contamination on the surface.
The epoxy will cure a little faster and subsequent coats should be applied wet on tacky, this avoids the sanding between coats.

Good luck and fair winds.

 

[ribrage]

I have used a product called "SP Eposeal 300" for a few years now. This is a very thin clear epoxy primer that soaks into the wood, it dries very quickly but can be used once mixed over several hours so long as it is kept in a jar with a top on. I apply several coats of this epoxy primer and then I finish off with several layers of yacht varnish.

BIG plus 1 for eposeal , we repaired our coach roof (timber) and used eposeal to run into some unnoticed delaminated ply before sanding and painting, stuff was like concrete, just keeping adding it in until no more can be asorbed, took a few days , but well worth the effort

 

[Tim Good]

Ok so that Eposeal seems like a good option... As for varnish most people say get the best UV protective stuff you can afford.

What varnish has the best UV protection nowadays?

 

[ribrage]

Ok so that Eposeal seems like a good option... As for varnish most people say get the best UV protective stuff you can afford.

What varnish has the best UV protection nowadays?

OH GOD , a varnish question is akin to an anchor question, theyll all be out from under their rocks now ! - Take a look at coelan , it works for me - its not cheap mind you, Ken Howles teak merchant in Poole did a teak yacht from scratch called cariad , completely coated it in the stuff , lasted for donkeys years as has mine