Friday, February 27, 2015
Raka Epoxy
In my last post about the debate among traditional boatbuilders regarding the use of epoxy resin, you could see two brands of epoxy formulated for boatbuilding in the photo. One, of course, is the well-known and widely popular West System, and the other, in the plastic one-gallon jugs is Raka Epoxy as shown above.
For about 8 years now, Raka has been my epoxy of choice. Before that I used System Three epoxy almost exclusively, and of course, Ive used a fair amount of West System. Like many, I believed that the major companies like West and System Three were the only ones that could be trusted, but then I began to meet and talk with other boatbuilders who were using Raka for both large and small projects. Everyone that used it liked it, and they were saving a lot of money on their materials lists as Raka has been consistently less expensive than the big name formulations. What finally convinced me of its suitability for building boats was the Bolger Nymph dinghy that my brother started building with this epoxy, but later abandoned before finishing the project. He had assembled the hull and laminated the fiberglass sheathing over the exterior, and then left the hull with the unpainted epoxy turned upside down out in the weather for more than a year. When he later gave me the hull so I could finish it and use it for a tender to my sailboat, Intensity, I examined the epoxy coatings and fillets and found nothing wrong with them at all. I completed the boat using the Raka epoxy he had left over, and it is still in service today.
After that experience I began using Raka to rebuild the interior of Intensity, then to build several small boats, including a few Backwoods Drifters. I found I preferred Raka epoxy for many reasons, and price was the least of them. For one thing, the viscosity is better for coating wood and wetting out fiberglass. I found this epoxy to excel at clear-coating wood that would later be finished bright, with varnish over the epoxy. There was less discoloration and darkening of the grain than with the epoxies I had used previously. Ive also found that Raka epoxy has less tendency to blush when curing, especially in the often humid conditions I work in here in Mississippi. I have yet to have a failure to cure or a bad batch, and as long as Ive been using it every order of Raka epoxy has performed the same. I can discern no difference in the strength of cured joints compared to the other epoxy brands, and I have never had a failure of any joint made with it.
The basic Raka formulation is mixed in a 2:1 ratio, using the 127 resin, and two choices of hardeners: the 610 fast and the 606 slow. Raka offers other formulations with different properties, but Ive found that these are all I need. The fast hardener is excellent in cold weather or for small, easily handled jobs in hot weather. The slow hardener is what you need for big laminating jobs where you need more working time, especially in hot weather. The two hardeners can also be combined in different combinations in larger batches, yielding a medium curing speed.
To learn more about Raka epoxy you can go to the company website and read the user manual: http://www.raka.com/UserManual.html There you will find a product description as well as instructions for proper use of the material. Raka is based in Ft. Pierce, Fl and the product is not found in retail stores, but can be ordered directly from Larry, the owner, by calling the telephone numbers on the website.
For another opinion on different epoxy formulations, read the results of this test performed by a wood-epoxy composite kayak builder on the One Ocean Kayak website. You can see how Raka performed as compared with the top name-brand epoxies.
http://www.oneoceankayaks.com/Epoxtest.htm
http://www.oneoceankayaks.com/Epoxresl.htm
No comments:
Post a Comment