Hey Guys
Came across a spray can of clear urethane at the auto supply shop.
It is used to spray a claer coating over mag wheels.
Just wondering if anyone has used this or similar as a finish coat on epoxy.
I did find some other clear urethane finish some time ago at the hardware store but it came out with a honey colored tinge to it and didn’t really harden.
Stayed rubbery
Cheers
Look for UV protection.
Marine clear coat is the ticket however you will need a good spray gun and compressor (HVLP).
Plus it is scratch resistant!
I’ve had successful results using 2 pak Urethane as a gloss coat over epoxy, cans don’t give quite the same results and vary in quality alot, depending on the size of the board you would probably need 3-4 cans, so I’d look for a good 2 part veriaty.
Thin it a little and it can be applied by hand with a brush, sponge or lint free cloth, but be prepaired to do 3 or 4 coats and rub out, buff and shine, like a normal gloss coat, a lot of work but it will give a deep shine.
Its really made for spraying but as well as the compressor and spray gun you’ll also need a really good face mask, i’ts not the nicest chem to work with.
I have done three “rattle can” gloss coats on RR epoxy, all with good results. And I bought the least expensive stuff on the shelf at Home Depot. Four years later and number one is good. You still have to wet sand and polish to get the texture down.
Aloha mds,
All true varnishes tend to yellow or amber especially with age, with the exception of water based finishes which aren’t true varnishes. Water based finishes, while non yellowing, are usually a lot more cloudy. bland, less clear, and not nearly as weather protective.
There are so many myths and misconceptions associated with finishes, especially varnish and oil finishes. To keep this on topic, varnish for water craft is fine whether as a finish over bare wood, epoxy, or many other surfaces. A good quality varnish will usually have a better type resin with more resin solids added than a cheapo version. Historically, the sap from certain pine trees was used, but since the early 1900s synthetic resins have been developed. A myth is that exterior spar and marine varnishes are harder. Varnishes are manufactured with a mixture of oils and driers. “Spar” or “marine” simply means the varnish is a “long oil” varnish and has a higher ratio of oil in the mixture which allows the finish to expand and contract with humidity and weather conditions more so than “interior” varnish. A “short oil” varnish made with low amount of oils is harder but more brittle and can crack with weather conditions.
You can apply a varnish with a brush with great results, but the big downside to varnish is that it requires a lot of patience. it takes a long time to cure, you must sand each coat to enable the subsequent coat to adhere, it takes several coats to achieve the desired finish, and if you want a mirror gloss finish you have to “rub out” the final coat with super fine grits (historically with pumice and rottenstone).
Bottom line: Use varnish spray or brush, but the type and quality you want dependent upon the useage and what you want the finish to do. If you want the best, I would suggest going to a high end paint store and get one of the two-part polyurethane varnishes and take the time to “apply” it by hand brushed coats. A compromise would be any of the spray “exterior” versions available almost anywhere.
Enjoy the ride!
richard
Hey Guys
Seems to be creating more work than is needed.
Was sort of looking for a speed coat alturnative instead of use acrylic.
I think I will stick to my usual sanded epoxy gloss coat.
Cheers
Good call. “Finishes” won’t hold up. No reason to reinvent the wheel so keep it simple. Now if you decide not to glass, but to put a finish directly on a wood board…different story (see above).
Richard
MDS,
A few years back, someone on Swaylocks turned me on to UPOL, and now I swear by it. One can will do a longboard, or a couple of shortboards. You can find it at auto paint supply stores. Pricey, but works great, dries quick, sands great if you need it.
I think I will stick to my usual sanded epoxy gloss coat.
Good for you!
I thought that people down under preferred white boards?
Sorry for my ignorance!
Don’t use it on polyester resin or it will flake off.
Seagun, thats the brand I use, but not the cans, I use UPOL crystal clear fast drying low Voc, 2 pak, 3:1 mix ratio, apply just like a polyester gloss coate, but needs 3 coats so it is more mork, but its the closest think I’ve found to a polygloss, and it will adhear to epoxy.
I think epoxy a more versitile resin then poly, but one of the down sides is the effort it takes to get a gloss coat that comes anywhere near that of a good poly gloss.
Polyurethane is definately the way to go, but go for a waterbased “clear coat” variety, not an oil based one. the oilbased “varnish” variety as these yellow.
If your going for speed and to reduce the amount of work then stick with polished epoxy finishing coat or acrylic, much easier/quicker, the results good but just not as good as they can be, which is where I try to aim.