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View Full Version : Best way to get a consistent satin finish using DWX epoxy resin



fliflicker
12-18-2016, 12:19 PM
Hey folks, I'm building my first boat, an 8' stitch and glue pram. I hope to start lofting next week but I like to plan ahead. I want the boat to have a natural wood interior that has more of a satin finish rather than a shiny one. What is the best way to finish a natural wood interior and end up with a solid satin finish. I plan to use DWX epoxy resin on Okoume BS 1088 plywood. Your thoughts?
Thanks for your help! Doug

phiil
12-18-2016, 12:52 PM
Satin varnish. You need it to protect the epoxy anyway;

Todd Bradshaw
12-18-2016, 05:45 PM
Yep, put on about three thin coats of epoxy resin, give it about a week to fully cure, sand it smooth (because it won't be) up to about 120-150 grit and then varnish it with a satin varnish containing a good UV filter.

Eric Hvalsoe
12-19-2016, 01:19 PM
Most satin varnishes don't possess the uv protection of gloss spar. If epoxy degradation from uv is a concern, than gloss should be applied over the epoxy, and can be topped by satin.

fliflicker
12-19-2016, 01:38 PM
So cover with a few coats of UV spar gloss than satin... Thanks!

Phil Y
12-19-2016, 03:35 PM
And then 3 coats of your favourite paint. Either now or in a few years time, when varnished ply does what varnished ply does!

Eric Hvalsoe
12-19-2016, 04:21 PM
So cover with a few coats of UV spar gloss than satin... Thanks!
Yes, I mean if it is really going to be exposed to the weather. This is what CLC, among others, recommends with their kits. Man'o'war claims to have a satin varnish with UV for indoor and outdoor use. A staff person at the Fisheries Supply paint counter scoffed at the claim. I have not tested it.

Todd Bradshaw
12-19-2016, 05:23 PM
There is no reason that HALS (hindered mine light stabilizers) and UVA additives can't be added to satin varnishes by the manufacturers. The thing that makes them satin in the first place is the addition of finely ground minerals to the varnish formula. Since you generally want to build up several coats on marine varnishing jobs, it is a good idea to use gloss varnish for the base coats and finally top that with a coat or two of satin. This is because multiple coats of satin can get a bit cloudy due to the mineral content. Also be aware that there is usually somewhat better protection from gloss varnishes and paints because the shiny surface reflects more of the sunlight away. UV protection is not a one-time, permanent thing. If your surface is going to see a fair bit of UV some of these protective substances it contains get slowly used up as they do their jobs. They need to be refreshed (recoated) from time to time in order to prevent failure. How often depends on how much exposure they get.

Here is one satin varnish with UV protection added.

http://www.homedepot.com/catalog/productImages/1000/f7/f7b7f076-c412-4b86-9e7f-5e988be0dfe8_1000.jpg

Mike Seibert
12-19-2016, 08:18 PM
I am planning to do something similar on my Lightning. I will be using Epifanes varnish. The Epifanes approach to this is to put several coats of regular varnish on first, which will provide the UV protection you need, and then to put one or two coats of satin on top of the glossy varnish to get the look you are going for. I haven't tried it yet, but will be doing that in the next couple of months.

Eric Hvalsoe
12-19-2016, 10:26 PM
My experience with fast drying water base varnish is not extensive, and not particularly positive.

Otter99
12-19-2016, 11:10 PM
System 3 Satin varnish, a polyurethane I think, goes on easy and no sanding between coats if you re-coat within 12 hours. I like the results and application ease. UV protection too.

jpatrick
12-20-2016, 11:12 AM
Also be aware that there is usually somewhat better protection from gloss varnishes and paints because the shiny surface reflects more of the sunlight away.




Todd, are you sure that this statement is true? Because I have always understood that what makes a good gloss finish looks so nice is that the light passes through the film finish, hits the impeccably prepared wood surface, and is reflected back through the film to the viewer. The more coats of finish then the thicker the film and the better the finish looks because of what we perceive as "depth." Under this scenario, the light must easily pass through the finish, not be reflected by it.

Jeff

Todd Bradshaw
12-20-2016, 12:13 PM
This isn't where I originally got the info years ago, but it's the first one I found today and is from an Epifanes FAQ. Don't know why the title is in Ruski - maybe they hacked it. :) These days if you search "varnish" and "UV" you end up having to sort through lots and lots of references to UV-cured varnish, which is a big deal these days for factory production but not what we're after.

http://ru.epifanes.com/qanda.htm


Question: I have read in a number of places over the years about a varnished finish that is either hand-rubbed or has a hand-rubbed effect or look to it. Could you explain what that means? Is it a special procedure and, if so, how is it accomplished?

Answer: In the old days, the only way to obtain anything except a high gloss finish in a varnish was to “rub it by hand”. Obviously, it was a labor intensive, time-consuming procedure. These days, we can reproduce that look in a single (or two-part) part finish right out of the can. “Rubbed Effect” varnish describes the degree of gloss. Somewhere between a semi gloss, satin or eggshell finish. This degree of gloss is perfect for an interior although it is sometimes used in exterior applications. Rubbed Effect Finishes are generally quick to dry, and easier to maintain. Our Rubbed Effect Varnish contains urethane resins which produce a harder , more scratch resistant finish. We recommend building up from bare wood with a gloss finish and topcoating with the Rubbed Effect, simply for the effect. This accomplishes two things. Gloss finishes are more weather resistant and offer better protection against UV and weather. Building up with 3-4 coats of this before the Rubbed Effect will maximize protection. Secondly, the build-up of gloss gives the overall appearance of the finish more depth and clarity. Epifanes does manufacture a version of Rubbed Effect called Woodfinish Matte. This is one of the only “Rubbed Effect” finishes containing U.V. filters. This addition makes it very suitable for exterior use. It is often used on the inside of Canoes and Kayaks where a non-glare finish is desired.

Paul356
12-20-2016, 01:10 PM
DWX epoxy is not designed for clear coating. So I was told by Chuck L, after I has some issues with it on what I thought would be routine coating and buildup on some panels.. My 3d coat was not good, and I had to sand a lot of it off. I was able to apply a first coat fine with a plastic scraper ("bondo tool"), and a second was ok for the most part either with the same scraper or, as I recall, a brush in some cases. The third was not good, whether brushed or rolled. It did not adhere, and it blistered and puckered severely. In any event, do not count on DWX as a clear coat as we normally think of it, at least not without checking further.

fliflicker
12-20-2016, 03:11 PM
Seriously? What's up with that? Has anyone else had trouble with multiple coats of DWX epoxy. How many coats of epoxy are needed to seal the wood assuming multiple coats of varnish will be applied?

David G
12-20-2016, 03:16 PM
Zero - 3, normally.

MN Dave
12-21-2016, 11:50 AM
Straight epoxy resin is not formulated as a finish, so it lacks some of the additives that are used to make a paint flow out smoothly. David G may have more of a knack than most of us where it comes to painting with straight resin. I didn't get such good results with several coats.

Flatting agents include such things as fumed silica and diatomaceous earth. Search on the word flatting here (http://www.douglasandsturgess.com/mm5/merchant.mvc).

Read this: The Role of Flatting Agent in Creating Sheen [not Charlie] (http://news.thefinishingstore.com/index.php/the-role-of-flatting-agent-in-creating-sheen/)
If the dust in the finish reduces durability, I suspect that it is more due to the increased surface area, the vulnerability of the raised spots to damage and tendency to hold contamination. The lumps formed by the particles are more easily abraded. It is more difficult to clean a flat paint that has been exposed to something like a pesticide, and that some powders added to paints are more difficult to decontaminate than others. look up cbrn.

Reflection: I don't think that flatting reduces the amount of reflected light. It blurs the reflections, making them look dimmer. https://en.wikipedia.org/wiki/Gloss_(optics)

'Flattening varnish' on google (https://www.google.com/search?q=flattening+varnish&ie=utf-8&oe=utf-8)