How to Use Epoxy, Part 1 – Coating Plywood for a Paint or Varnish Finish

epoxies are known to be used for bonding wood together gluing wood together but it can also be used for coating surfaces in this video series we brought you to the Brooklyn boat yard where we use epoxy everyday to build high-end boats I'm going to show you the best tips and tricks we've learned over the years and using epoxy to clear coat a surface for paint and varnish and how to use epoxy with fiberglass cloth and dine L to get perfect decks and cabin tops let's start with how to clear coat with epoxy and create a beautiful smooth and waterproof surface for surfaces that are gonna be painted or varnished some things that you may want to have the roller that we use for epoxy work in the boat yard it's a very thin nap foam roller the thicker these get the more glue and the more mess you tend to make so for for finishing epoxy clear we use something like this these common 7 inch that you would put on a typical roller cage but this is just a small three-inch just a stock 3-inch foam brush it for tipping out and also a chip brush which we'll talk about the use for tipping with something like that we use primarily west system epoxy in the shop we always have and you know your typical basic epoxy whether it's many companies have typically a fast cure a slow cure and then some kind of a special clear coating style epoxy and I want to show the benefits of both we have these metered pumps that as you open the valve and crank them out it's already metered at the proper ratio epoxy can be mixed by volume using you know your basic painters cup whether it's 5 to 1 mix ratio which is what the with the west system fast is or three to one you want to be very clear of your ratio all epoxies are different and mixing them by volume and a cup like that so long as you stick to the resin and hardener ratio you never you won't have a problem we use such large quantities of this that we have these kind of metered pumps you walk up you throw the valve open you take with you and you walk away you don't think about it pair gloves is always key let's start with the West system fast this is their stock fastest cure time epoxy basically when you are clear coating and rolling and tipping you want to be able to put as many coats as you can on to build up a thickness if you're painting it if you're varnishing it typically you would only want two coats so it doesn't get marque but fast enables you want a painted surface to apply one over the other or over a period of time up to four coats over the course of an eight-hour day which is a nice thick buildup that gives you the ability to sand that out and have an epoxy sealed surface one thing with the 205 over time the hardener gets a real red color which is an Amber that is going to change the tone of your wood just something to be aware of the 207 which is the epoxy that the weft system sells for clear coating is a different ratio it's three to one but when it comes out very clear there's a very very slight number to present but nothing at all like the 205 it's also a much thinner epoxy than the 205 the 205 is a little bit thicker and consistency but both are used for what we're about to do so let's get back over to our panel and have a look we're gonna start with a 205 and we'll just do one small panel of that to give us a comparison you want to mix this very thoroughly say a couple minutes of mixing all idea is that you're building a surface here that is gonna fill the grain and give you a paintable surface that is sealed from moisture a big mistake that I see guys make is that they dip their roller in and they've got a lot more glue on some parts of the roller than the others and when you go to roll that on that's how it comes off the roller and if you look at that these areas are coated with a very thick layer and these have none the idea is to get a very consistent surface is even of a surface as you can so that as you're sanding it you know a couple thousandths of an inch you would sand much of this epoxy off before you got to that layer to deep gloss that layer so the idea is whenever one coating is to use these ribs in your paint tray to get as even of a coat on that roller as possible and then to work that as evenly as you can you see the difference there between what I just did and by really thoroughly getting that epoxy on the foam roller and typically I will roll one direction and then the other you can see that the colour of this epoxy really changes the tone of the wood again it may be something you're after if it's a painted surface it doesn't matter and it allows you to get more coats on in a day using fast than the 207 typically anything that is going to be painted we would roll and coat with epoxy primer and then paint would go over that it gives it gives the wood a complete barrier if something is going to be finished bright typically we only epoxy coat wood that is going to be finished with a two-part automotive style finish if something is going to be finished with varnish while you can varnish over clear coated epoxy it is it is a very very difficult thing to maintain the longevity of that going down the road to block out varnish 10-years varnish really should be stripped and then not only are you stripping varnish but you're having a strip back through that epoxy sanding out all that epoxy which is a much more difficult thing to do than just heat gunning and scraping back varnish epoxy clear coating is a very durable surface and what is actually required of a two-part automotive clear varnish but not something I would necessarily recommend to be put on and varnished over with a single part varnish another place that you see epoxy clear coating overused is on solid wood joinery solid wood has the ability to come and go it moves there's no stopping it an epoxy if coating is a very very non incredibly flexible sealer epoxy coating would be used on something that is plywood base construction that maybe veneered inside and out so it has the appearance of traditional joinery but is very much a monocoque structure now let's go to our 207 again this is epoxy that is sold as a clear coating epoxy and it's thinner it's not as viscous it is very much a clear finish like the 205 and again applied much the same way roll you see I'm getting as much on the surface as I can as evenly as I can I'm going 90 degrees to the grain and then cross grain and what I want to demonstrate here is what it is like to leave something as evenly put on as you can buy a roll or a loan and then something that is rolled and tipped we can do that right next to this and once the epoxy is set up we can sand those out and have a look at the differences that is about as even as I can get something put on with a roller again I applied 90 degrees to the grain went with the grain and then finished 90 degrees to the grain the next thing I'd like to demonstrate is a role than tipped epoxy coating and this is something you're gonna varnish and you want to get on as evenly as possible so that as you sand it you're not burning through epoxy can be overworked and when you overwork epoxy you introduce air to it and it almost muddies the surface it gives you kind of a slight murky look and I can demonstrate that here I am working that epoxy way more than you would need to and you can see that eventually it gets a milky a milky look sometimes that will eventually work itself out as the epoxy sets up but something you want to avoid this basically just apply it as evenly as you can once we've applied as evenly as we can and I will dip a little bit with that foam brush and with the grain much like varnish I am tipping in the direction of the the grain of the wood and that just levels out that texture again that's left by the roller and you can overwork it typically on smaller parts I will use a foam brush on larger areas like varnish you would roll a section just maybe two feet wide tip that out move over roll another section out and overlap your tipping just like varnish many thin coats is better than one or two very thick coats especially when you're getting into finishing something bright another thing that I wanted to show you was if you're using a chip brush to tip epoxy out not all chip brushes are created equal well these are both throwaway disposable type brushes this is kind of your el cheapo version of a chip brush you use one of these in epoxy because of the viscosity of the epoxy you're gonna lose about one third of those bristles they're just a very cheap throwaway brush while this may be a three dollar brush this may be four dollars and fifty cents it's they're called a fooler and this is what I use for any kind of a tipping in varnish buildup or epoxy a much higher quality disposable chip brush chances are with epoxy with varnish it's gonna pull a bristle out of the brush you can see there's a so right there the time to get that bristle out is right now and how you do that is by stabbing by stabbing and grabbing it out and then tipping back through that area leaving bristles in your finish is something that you just have to sand out if it's gonna be finished clear if that bristle is across the grain it's something that in close inspection you'll see that so you want to use a high-quality brush if you are gonna tip and the time to get those bristles out is as soon as you see them epoxy like varnish once you actually coat something in five minutes later you go back and you say oh man there's a bristle there it's not the time to go after it you'll make more of a mess and more of a crater trying to get that bristle out than if you do it straight away so after you know 10 or 15 minutes it's too late I would say just forget about it and walk away the bristle right there and again you just quickly stab it with your brush and then brush through it typically to put successive coats on you have to wait until the epoxy is called B stage which is not fully cured but in the curing phases and the the 205 will reach that point faster than the 207 and we're gonna let these sit and come back and I'll show you guys the optimum time to put a second coat on these so for demonstration purposes I just use this little 3-inch foam roller any hardware store carries this kind of thing you really want to stay away from anything with a with a nap or a hair and variably that comes off in your finish and gives you a much more textured finish than your after on anything larger I would move to a 7 inch version of this that goes right on a conventional paint roller but just to kind of give you a look at the different tools you may run into so we've just come back to our panel and the fast 205 is tacky but not necessarily coming off on your glove and that is the perfect time to recoat it's what's called be staged that's going to happen a lot faster with 2:05 than the 207 typically we only get two coats of 207 on in a day the clear coating epoxy 205 again on a painted surface something that you're not worried about the patina changing the color and you want a nice thick build up you could get three if not four coats of epoxy rolled on to this over the course of the day if you catch it at the right time now is the right time to apply a second coat so again you want to get the the roller nice and even and do is need of a job as you can rolling you can feel the epoxy coming off the roller if it chunk chunk chunk that means that you have thick thin spots on your roller you really want to work that out into a nice even Sheen without overworking the epoxy and introducing air that's gonna make it opaque not as big of a deal and something that is gonna be painted but certainly a big deal in something that you want to varnish later we're gonna tip that out with a three inch foam brush just nice even strokes this 207 is more primed to be top coated want to apply epoxy to this like I see epoxy applied a lot which is just fine the pop hazard leaked and not in a very neat way and kind of to demonstrate the importance of putting on an incredibly even layer and then tipping it out with a brush and that'll become evident as we start to sand that our second panel here where we're rolling and tipping even their mental help show the differences and the importance of applying it as evenly as possible next in the series we'll talk through sanding these out and getting a nice smooth paint or varnish surface you

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