Epifanes use/misuse

[dancrane]

I'm hoping to get ahead of the game by giving the pieces of ply I bought for various jobs on board, a few coats of Epifanes even before I start cutting it up.

Is this a lousy idea? I was thinking that by the time it's all measured, cut and glued/screwed in place, some parts will be hard to reach and I won't much relish delays.

Obviously the cut edges will need further varnishing but I'm hoping to minimise the job on site.

The instructions say it's dry after 24hrs at 18°c. Assuming my garage won't get that warm till next month anyway, how long is required between coats at, say, 12°?

Thanks.

 

[david_bagshaw]

Unless 2 pack, or only a thinned coat, it will take ages to cure hard enough that the tools dont scuff the coats off.

 

[Seashoreman]

Unless 2 pack, or only a thinned coat, it will take ages to cure hard enough that the tools dont scuff the coats off.

I would agree with this after using a few litres of Epifanes Rapiclear for interior teakwork in cold workshop and on board. Can be touch dry in 4 hours but needs days to really toughen up. Coated rubbing strakes in the sun last weekend, recoated in 6 hours no problems.
I agree that a thinned coat could act as a primer/sealer. Cant you cut them to size before fitting?

 

[dancrane]

Can't you cut them to size before fitting?

Thanks for your thoughts. I'm not near enough to the boat to judge well just how big the pieces need to be, but since I have the ply and the varnish here, I'd hoped to get ahead.

But once I'm able to visit the boat, it'll (hopefully) be warmer anyway so last-minute varnishing needn't take days and days to dry.

2nd question: I'll be using a powerful glue to attach a sheet of 5mm marine ply to a gap in the GRP bulkhead; ought the glue be applied to bare ply, or after coating with Epifanes?

 

[Seashoreman]

Thanks for your thoughts. I'm not near enough to the boat to judge well just how big the pieces need to be, but since I have the ply and the varnish here, I'd hoped to get ahead.

But once I'm able to visit the boat, it'll (hopefully) be warmer anyway so last-minute varnishing needn't take days and days to dry.

2nd question: I'll be using a powerful glue to attach a sheet of 5mm marine ply to a gap in the GRP bulkhead; ought the glue be applied to bare ply, or after coating with Epifanes?

Dan its not a question of days to dry, it is a case of days to 'cure', get tough and hard enough to risk abrasion. You can build 3 or 4 coats but it can still take a few days in warm temps.
I would suggest that raw wood is best glued 'bare' as opposed to glueing to varnish. I am not an expert on modern powerful stuff though.
One thinned coat on ply will seal it and speed up the job of finishing it. I have done this successfully with white spirit.

 

[dancrane]

Good advice, thanks a lot! :encouragement:

 

[prv]

I have some parts for my new chart table arrangement which I'm in the process of varnishing.

I optimistically thought I could do a sand and recoat every evening after work; I used to do one coat per day on Kindred Spirit's spars, but they generally dried quicker in the sun than these bits in my shed. I did the thinned coats Sunday, Monday and Tuesday (50%, 25%, 10%), but sanding the 25 ready for the 10 was a bit dubious and I should really have left it. I skipped last night as it was definitely still too soft; I'm about to go down and hopefully do the first full-strength coat now.

I think I'll leave it at one every other day now (two of standard epifanes, two of rubbed-effect). If I keep that up I'll put the last coat on on Wednesday night, then maybe by Sunday it will be hard enough to withstand being bashed about while I shoehorn it into place (it's a convoluted process).

Pete

 

[itchenseadog]

Epiphanes do an accelerator to add to their varnish. I use about 5% in a litre together with about 5% thinners. Should be touch dry in 5/6 hrs and fully cured next day. Makes no difference to gloss or flow. Marineware will have stock.

 

[Davegriff]

2nd question: I'll be using a powerful glue to attach a sheet of 5mm marine ply to a gap in the GRP bulkhead; ought the glue be applied to bare ply, or after coating with Epifanes?

No matter how strong the 'glue' is, if you apply it over the varnish, the bond will never be stronger than the varnish itself. Always apply adhesive directly to the wood, glass fibre or whatever.

 

[dancrane]

Hmm, thanks Davegriff.

Regarding thinners, it's all looking more complicated than I expected - or hoped! Does Epifanes require a specific thinner?

The work I'm looking at is hinged panels of 12mm, as load-spreaders on the trolley, as well as 5mm stuff to replace the missing rear cockpit bulkhead. Some of it will be hard to fit...

...and impossible to re-coat with varnish once it's glued in place. The point being, none of my woodwork will be much on show - I just want it coated for its own preservation.

So, keeping it simple, can I start with a dilute mix, do a second, less-dilute coat once the first is properly cured, then a final pure varnish coat?

 

[Davegriff]

Don't know much about Epiphanes, but I've always used varnish with a thinned first coat and see no harm with a follow up thinned coat apart from maybe loss of gloss. You could pre-varnish everything except where the adhesive will be.

 

[dancrane]

Cheers! :encouragement:

 

[prv]

Don't know much about Epiphanes, but I've always used varnish with a thinned first coat and see no harm with a follow up thinned coat apart from maybe loss of gloss.

The "official" recipe for epifanes is as I described above - first coat thinned 50/50, which is very thin and soaks right in, second coat thinned 75/25, and third thinned 90/10. Then as many coats of unthinned as appropriate for the purpose; for new interior woodwork I generally go for at least four (for a total of seven coats).

I have to say, if I was in Dan's position I wouldn't be using varnish at all. The benefit of varnish is aesthetic; for things like bits of trailer and the back of a utilitarian repair it's a nonsense. Both of these would be better with epoxy for protection; one coat will do the job, two at the most, and be done in an hour or two. If exposed to sunlight, perhaps slap some paint over the top, any will do, though I query how big a deal the "epoxy and uv" thing is in the uk anyway. In the case of the bulkhead-fixing board, the soaked-in epoxy will provide an ideal base for the thickened epoxy you use to glue it in place; do it while the painted-on coat is still gelling and you'll have a true chemical bond.

(The varnish work in my shed was perfect after the extra 24hrs, by the way. Nice and hard, and flatted down easily with a bit of 320 grit.)

Pete

 

[chewi]

Don't know much about Epiphanes, but I've always used varnish with a thinned first coat and see no harm with a follow up thinned coat apart from maybe loss of gloss. You could pre-varnish everything except where the adhesive will be.

i bought epifanes rapidcoat and Force 4 advised some thinners as it would give a better finish. Reading the tin later it specifically said not to thin it.. Since then I have been more sceptical of a chandlers advice, some might be better than shelffillers, but they can only use what experience they have, which won't be all brands of varnish!

 

[prv]

i bought epifanes rapidcoat and Force 4 advised some thinners as it would give a better finish.

That's not varnish as such though, I don't think. More a modern-style woodfinish under the epifanes brand.

Pete

 

[chewi]

That's not varnish as such though, I don't think. More a modern-style woodfinish under the epifanes brand.

Pete

Its difficult for the yottie on the street to know the difference . Is "varnish as such" tung oil based?

 

[dancrane]

...if I was in Dan's position I wouldn't be using varnish at all...epoxy for protection; one coat will do the job, two at the most, and be done in an hour or two. In the case of the bulkhead-fixing board, the soaked-in epoxy will provide an ideal base for the thickened epoxy you use to glue it in place; do it while the painted-on coat is still gelling and you'll have a true chemical bond.

Ah... :hopeless: What a pity there's no smiley to match my deep sense of ignorance! Thanks Pete. Well, I still have my Force 4 receipt and I haven't opened the varnish yet. Can you recommend a type/brand of epoxy - ideally available in small quantities, at reasonable cost?

 

[prv]

Can you recommend a type/brand of epoxy - ideally available in small quantities, at reasonable cost?

Force 4 sell both SP and West, generally the smaller pack sizes. I have a habitual bias towards West but I think both are equally good.

Unfortunately epoxy is never exactly cheap - though neither is epifanes for that matter, especially if you use their thinners (I do). If you really wanted a budget approach you could try using polyester resin in the same way as epoxy - I've never tried that though so I don't really know how well it would work.

Pete

 

[dancrane]

Cheers Pete. Do me a big favour: click here and tell me which of these (if any) I want? I'm really in the dark here! http://chandlery.force4.co.uk/search#w=west epoxy

 

[itchenseadog]

Epiphanes Rapid coat can be used as a base coat for their gloss varnish (recommended to me by the Epiphanes rep some years ago). Epiphanes thinner is white spirit based and therefore it's ok to use white spirit as a thinner on their gloss varnish.