Lunkerville said:
nbaffaro said:
Two part epoxy is going to be the better of the two for this application.
However, epoxy is more expensive and harder to work with than water sealer.
Was thinking of using epoxy myself, exactly how hard is it to apply? Can someone descibe the process they used?
thanks
Two part epoxy isn't difficult to learn, however, It is more difficult than water sealant. Basically you buy a 'system' of epoxy. There are many brands and some have better specs than others; but for what we use it for, as a protectant, even the cheapest epoxy will work well. I use MarinePoxy and System 3 depending on what I am doing, but most of my work is structural. Having said that, MarinePoxy has VERY good specs and I use it planing boats as awell as general protectorant work.
Epoxy has a mix ratio, like 3:1 or 2:1, you MUST mix it according to VOLUME. Most people use pumps that dispense exactly One Ounce of epoxy, then you just pump once for Part A and twice for Part B, easy enough. If doing large areas, like the bottom of a hull, you will need to have graduated mixing cups otherwise it will take days to finish. If you screw up the mix it will not cure, ever. I have some sitting in a cup that has been sitting for six months that was mixed wrong and it is still soupy.
Application is done one of several ways:
Epoxy proof roller- this is a high density foam paint roller
Brush- I use chip brushes for most work except finishing, then I use a finishing brush.
Spray- Special breathing apparatus is required to spray Epoxy, do not spray unless you know what you are doing.
Squeegee- Like a Bondo spreader, moves lots of epoxy around fast and leaves a thin layer behind. Very good for large laminations.
Really, it's as easy as mixing it up and putting it on the wood. I use a minimum of three coats.
Most epoxies have hardeners specific to a temperature; in fact all hardeners are specific to a temperature range. But you can also usually get different speed hardeners, many times, for the same epoxy. For instance I use Fast, Medium and Slow hardeners based on the temperature. Slow for very hot times, medium for cooler times and fast for cold times. Using these hardeners will yield very close cure times across a vast temperature range; from about 32 degrees to 100+ degrees. So your cure time will be close to the same for 40 degrees and 90 degrees, but with different hardeners, fast and slow.
Avoid at all costs the Poly and Vinyl Ester epoxies, like Bondo. They will allow water infiltration, they are cheaper however, but you will pay for it in the long run with rotted wood. Poly and Vinyl Ester epoxies will work well on FRB or FRP wher the core is NOT wood; the worst that could happen is some small blistering.
the biggest difference in water sealer and epoxy when it comes to working it is cure times; there's just no getting around cure times with epoxy and while it is wet you can't do anything with it.
Adding a fiberglass mat or tape will allow the use of smaller core materials that have a very high strength; and is the next step in learning to work with epoxy.
It really isn't that hard to learn.