Yeah I know, I blew it, should have measured a little more carefully. What can I do now? The gloss is almost hard but still feels sticky to the touch and its been 36 hours. Will it continue to harden over time? Should I heat it up? Will I be forced to scrape with a razor blade? What advice do you guys have?
It may take weeks, but it will eventually harden. Resist the temptation to heat it (even in the sun), you’ll have bigger problems if you do it. The best way to avoid this problem next time is to use a cheap kitchen spring scale and weigh it. Put your empty container on the scale, pour in the epoxy to the volume you want near an even mark on the scale. Multipy this weight by .45, and add the epoxy weight to that figure. Pour in your hardener until the total weight equals your calculated number and stir with a paint stick for at least 3 mins. Here’s a whole thread on this subject: www.swaylocks.com/forum/gforum.cgi?post=347303;search_string=epoxy%2Bscale;#347303
Heat it up, it’s the only thing left to try.
If it’s really cold where you are, or you’re using slow hardener, 36 hours might not be too suprising, there could be hope.
Just be careful how hot you get it if you are using EPS! vent the board, either with the vent, or by drilling an inconspicuous little hole somewhere if you don’t have a vent
Carefull of the heat if you are using PU as well of course
*Edit - Ha, Petes reply came through just before mine, with contradictory advice! If you are carefull you can heat it! *
Also, if it is just temperature that is preventing hardening, your board will be much weaker for a long time if you let it cure without heat.
I think of postcuring as almost essential, unless using fast hardeners in a warm climate. Even then i would post cure, but I 'spose I am set up to do it so it’s no worries
Epoxy can be hard enough to sand, while only being half as strong as it should be, so the fact that it is sandable is not always an indication
HDT is the best guide! (Heat distortion temperature)
You could try heating the resin that is left in the mixing cup, and see if it will harden.
If you are paranoid, keep the last bit of resin from your mixing cup, subject it to the same treatment as the board. Then you can heat that up, and be shocked when it goes all rubbery at a very low temperature!
I measure all my 3:1 epoxy by volume and have never had a problem. What I do is buy a extra large bag of clear plastic cups from the store. I take the first cup and pour 3 parts water. I mark the water line with a sharpie. Then I add one part water and make another line. Then I pour out the water and cut a holes in the cup where the lines are and set the second cup inside the first cup. I use my sharpie to mark the second cup through the holes. Now the second cup will act as a marking template for all the other cups. Remember that the marking template cup is not acurate to measure resin directly becuase the lines are off set to account for the distance that the cups off set each other when stacked inside one another. All I have to do is place the template cup inside a new cup and trace the lines from the template cup to the new cup and I have a cup with acurate lines to mix epoxy with. It is a quick and repeatable process.
Hey surfingisfun,
Try brushing a little bit of hardener on the board.
I spilled some resin on the floor in my shop and brushed some hardener over it - it seems to have completely cured.
Maybe I got lucky but it’s worth a try if you’re gonna have to scape it anyway.
~Brian
I use slow epoxy that takes about 24h to cure in a temperature of 20 Celsius/68 Fahrenheit. Meaning that in 24h it has cured so that you can touch and maybe even sand it a little. For it to cure completely i have to let it cure for atleast 4 days. I have experienced troubble with the epoxy one time when the power was out and the temperature dropped fast in my shaping room just as i was done with some ding repairs. I guess it was like 2 Celsius/35 Fahrenheit in there, or less, just above freezing. That epoxy never hardened completely, it was like chewinggum and had to be removed with tools and replaced. Heating epoxy is a good idea but it has to be done slow. Bring it up from 20 C/68 F to 40 C/104 F in two hours and let it cure. This procedure makes it cure much faster (24-36hours and it’s like rock) and you get the advantage of harder epoxy (This is great for fins). This is a tricky procedure however since the air trapped inside the board expands and can make bubbles in/under your epoxy. Vent it if possible but most important, heat it up slowly avoiding sunlight.