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fiberglass and epoxy slow curing at two spots.
On one side at the bow and stern of my hybrid shearwater 17 I find the fiberglas and epoxy remains soft. I've been pretty consistent in mixing harderner and resin but it seems likely I've goofed up somewhere. The spots are relatively small maybe a foot along right at the shear clamp of the inverted kayak and not above it. Is there anything to be done to activate the hardener in these areas? ? Heat from a hair dryer? Applying resin to those areas? It's just about 24 hours after I applied the epoxy. Everything else in cured.
3 replies:
RE: fiberglass and epoxy slow curing at two spots.
Thanks Howard for the suggestions. You're right the "soft spots" ae just that, soft not wet and I think they are begining to set up. So I'll be patient. I may be wrong but the areas seem to be near the points of the bow and stern at places where the side of the boat is steepest, most vertical, and since the fiberglass epoxy mix was applied while the boat was turned upside down these may be the areas where the mix may have run down a bit and collected at the shear clamp. I'm keeping the workroom warm and continuing to sand down rough spots while everything cures. Thanks for your help.
RE: fiberglass and epoxy slow curing at two spots.
One thing you can always do is buy one of those cheap "work lights" and aim it at the soft spots to help along the curing. I did this through the winter in my (unheated) garage to great success.
These types of fixtures - http://www.amazon.com/Bayco-SL-300-Clamp-Aluminum-Reflector/dp/B007RKKEHA (although they're much cheaper at your local harbor freight) along with a 100 watt bulb work great. Those bulbs are getting harder and harder to find, so look for "heat lamps", which are basically the same thing they just throw off slightly less light.
When I fiberglassed my hull, the garage was around 40 degrees, but I had eight of these hanging close to the hull all along it's length. Worked great. I never had a batch of epoxy kick early on me :)
RE: fiberglass and epoxy slow curing at two spots.
» Submitted by hspira - Tue, 4/15/14 » 6:29 PM
if it is soft, but not wet (e.g., it has started to cure)....then just be patient. to the extent that you can keep the temperature above 70 degrees.....that should help it along.
sometimes if the mix was not properly proportioned or if the temperature is low, it can take a bit longer to cure, but the epoxy is rather tolerant of imprecise portion management.
it was not obvious from your post if the soft spots related to a particular batch of epoxy. as a practice i always keep the cup i mixed the batch in (just put it aside - never re-use) to confirm that the epoxy cures. (e.g., if it cures in the cup, it should cure on the boat). that said, it often cures faster in the cup then when spread out becuase it cools quicker when spread and cannot use its own heat to kick-off....so it is more dependent on the air temperature.
if it doesn't cure, you will remove the wet/partially cured epoxy, don't try to put good over bad. but i don't think you are there yet. let us know how it goes.
best
howard