Thread: Epoxy on Timber problems....help

Thankyou Par, ill do that. i'll report in when its done, thanks for your guidance.

Eagle 1.

Not sure if this helps but if I try to put normal varnish over two part glue the interface goes black. By normal varnish I mean single pack spar varnish etc. By two part glue I mean the standard two part glues in common usage that are epoxy based filled with a micro ballon or similar filler that dry virtually clear with a very very slight yellow tinge.
BUT if I coat them with two pack epoxy clear varnishes the interface stays clear.

It's important to understand there's a lot of products called "varnish" of which many aren't. You have to read the label, which will tell precisely what it is. Varnish will have just the waord varnish, while the urethane will have this word in it as well and it's not a varnish, but a urethane. There are different types of urethanes (including water based, which often have the word acrylic in there some place), but regualr varnishes are pretty much all the same.

The same applies to glue. There are two part glues that aren't epoxy. There's even a water based epoxy now, which is actually a modified urethane acrylic (it'll say so on the label.

As to which caused this problem, who knows, but compatibility issues need to be brought up with vendors and formulators, as they come up. Of course, they'll want the same precision about the exact products employed, as I've asked. In the end, it's usually best to stay with some level of "nepotism", which simply means use the same type of stuff. If you've used a two part LPU, don't try to put a single part oil base over it (as an example). As a rule, good primers solve these issues, but you can't use these on clear coats, so staying within the family (solvents, vehicles, pigments, base chemistry, etc.) is the logical way to go, to avoid incompatibility issues.

My heart goes out to you!
Just a question, could you have a blushing problem? Some epoxy blush quite a lot and cause trouble when you try and coat it.
Blushing often presents as a white cloudy coat on top of the epoxy.
Good Luck
Christine

The waxy film build up we call blush, usually affects the bond, which would become fairly apparent once he sanded to sand on it.

Spar vanish is the wrong material as it is linseed oil based and has a tendency to darken quickly with sunlight as well as being attach by microbes causing it to go black. This is a major cause of timber decking to go grey/blackish yet some still promote it.
You should have used a non yellowing polyurethane which many coating suppliers now call spar marine grade. Fortis 519 is great for this applicatio. I am currently using it on my 27" cayzer. Many of the professional boat builders swear by non-yellowing polyurethanes now.

As for the clear epoxy sheathing I have moved away from that due to discoloration (yellowing over time), blooming (due to moisture - white ghosting look). The epoxy is great for use as penetrating sealer / undercoat as it protects the timber. I use the Fortis Prime 820 diluted with pure methylated spirits(must be 100%) as penetrating sealer. Much cheaper than using the stuff from the states. You can then use a 2 pack non yellowing polyurethane color top coat. I then overcoat this with some clear for extra enhancement.
I used the Fortis Coat 519 high solids non yellowing polyurethane on my white beach deck. Needed 5 thin coats with 180 light sand between coats.

I agree that linseed oil will darken, but spar varnish takes a very long time to do so (many years) and must be left unattended, the whole time. A regularly maintained spar varnish surface, can last many decades and is easily repairable and maintainable, unlike single or 2 pack polyurethanes.

As to epoxy, you seem to not be using encapsulation techniques, with will cause "blooming", because the moisture content in the wood still changes (not so with encapsulation). Lastly, thinning epoxy by more more then just a few percent,dramatically changes the physical properties of the cured goo (no longer waterproof). Doing so without understanding what the resulting formulation will be, is not wise.

IMG_3815.jpgIMG_3895.jpgIMG_4102.jpgHi Par, and crew,

it turned out to be poor application in high humidity. I sanded back entirely, re epoxied, and had a two pack finish applied proffesionally. looks sweet. ( aloty of work condensed in that one line )

Par i sent you an email, did you get it?

Regards Jeremy

The boat finish looks great - but I can't help but notice the lawn and garden in the background looks just like mine - overgrown ! Is that the same for all boatbuilders ?

Originally Posted by bagman

. . . I can't help but notice the lawn and garden in the background looks just like mine - overgrown ! Is that the same for all boatbuilders ?

Yes . . .

Looks great Jeremy, way to go . . .

no.
mine is a dust-bowl.
with a few patches of grass that stubbornly refuses to die.

I have both grass and weeds, easily a 50/50 blend, which I think of as a hybrid sort of lawn. All is cut at 3", as I'm a indiscriminate mower.