I just pulled my board out of my “bake tent” for post cure and it has 2 three foot long bubbles where the glass pulled away from the foam. Only on the deck but unrideable. Since i have 3 more boards to post cure, I would like help on two questions: a) what do i do in the future to prevent this (see more detail below) b)can i do anything to salvage this (crying has not helped) like cut some glass and try to re-adheare with resin?
Detail: EPS 2 # blank, Red Devil Lightweight spackle mixed with Liquidtex Basic white. Two layers 6oz both sides, Resin Research standard hardner and Add F. Put on final gloss. Cured for 48 hours. Put under plastic in the back yard for 6 hours at 130 degrees. Total gas bubbles (i guess). I didnt think i need a vent with2#? could it be the spackle.
130 may have been too hot, but I can’t remember the limits off-hand. I would cut out the bubbles and mix up some epoxy and glue them back down using sand bags or plastic bags filled with water to keep the shape of the board. Then sand around the joints, put down a layer or two of 6 oz, fair, hotcoat, gloss if you already did before, then sand and polish everything. It won’t look perfect but it’ll be rideable.
thanks all for the reply: i am suicidal over this:
aloaf- what do you mean prebake?
Rachel-sounds like this is what i will do. How do i prevent this in the future. If you surf LC, let me know. will show you some of this and get your input-you always seem to be on target.
Atomized- no, the stringer stayed down. the bubble is on either side of the stringer, huge. I hot cut the foam and glued up the blank myself
An option recommended by Bert Burger with vacuumed compsands is to maintain vacuum during post cure. Another possible remedy for future boards might be to vent it. Leave vent open during post cure. Even a small hole drilled somewhere might allow venting during post cure. The hole could be fixed later. Ramping it up slowly after a full room temperature cure might be another end around.
An option recommended by Bert Burger with vacuumed compsands is to maintain vacuum during post cure. Another possible remedy for future boards might be to vent it. Leave vent open during post cure. Even a small hole drilled somewhere might allow venting during post cure. The hole could be fixed later. Ramping it up slowly after a full room temperature cure might be another end around.
John, i think i will try that. I noticed in a post last year that you had some vents. do you still have any? selling?
How long did you let the spackle dry? Please take pictures of the blank and inside of the glass where the bubble/delam occurred. What you want to see is if the glass has pulled lots of beads with it or not.
Most of the gassing that we’ve encountered has been usually at the glue seam along the stringer. Back when we started doing EPS/Epoxy, the EPS foam available was pretty inconsistent and we did have some gassing that could happen anywhere in the blank. As surfboard specific EPS became available those problems pretty much ended. The only time we see gassing now is from the gluing/ stringering. which has become pretty rare as the blank manucfaturer we use has improved in that department.
How long did you let the spackle dry? Please take pictures of the blank and inside of the glass where the bubble/delam occurred. What you want to see is if the glass has pulled lots of beads with it or not.
regards,
Dave_D
I will try to get pics. The spackle dried at least a week. Mostly spackle pulled off, not really any beads. What does this tell you?
Most of the gassing that we've encountered has been usually at the glue seam along the stringer. Back when we started doing EPS/Epoxy, the EPS foam available was pretty inconsistent and we did have some gassing that could happen anywhere in the blank. As surfboard specific EPS became available those problems pretty much ended. The only time we see gassing now is from the gluing/ stringering. which has become pretty rare as the blank manucfaturer we use has improved in that department.
the delam is between the stringer and each rail. I used Gorilla glue with a PVC stringer and eps 2#?
Ouch, man, that’s gotta hurt. I don’t know what to say to help with your process, but I can tell you what I don’t do… I don’t spackle since I don’t trust the bond between the epoxy/glass and a latex-based seal. In fact, the only delam I’ve ever had with RR was on a blank that I spackled. I know lots of folks use it without any problem, but I just see it as another place to fail. I do trust the bond between straight RR and EPS though…
As for post-curing, I’ve never done that either, never saw a need for it… Again, just another place to screw things up… I like to stick to what I know works.
Man, really bummed to hear about your “disaster”, but it sounds like it can be fixed. “We can rebuild it, gentlemen. We have the technology.”
Have you thought about drilling the leash plug hole as well as routing out fin box holes before oven curing? Maybe that would stop it from happening again.
My two bits here: I’m with John and Silly. I did a 2lb longboard, with spackle, no delam. I vented it with one vent on each side of the stringer. They definitely work independently of each other, and in the hot sun build up a lot of pressure. Maybe you don’t need to vent it for normal use, but for us backyarders I think it’s a good idea to have some sort of vent for the post cure. Let’s say you’re a production guy working with a fancy oven setup and glassing in a hot room, you can work out ways to post cure without venting. See some of PlusOneShaper’s posts, he has put great stuff up in the past. But for the glass at 65 degrees F then post cure set, a TINY hole drilled in the glass will do the job. Then smear some epoxy in there after it’s post cured.
Good luck with the other boards, and the repair on this one.
Some things I see: Too much acrylic can make the spackle non-permiable, preventing the epoxy from saturating through the spackle into the foam, which is absolutely critical. Too much spackle will do the same thing due to sheer depth. If the spackle isn’t completely dry when the board is glassed, you could have a delam. I dry mine in the postcure oven to be sure, as it’s humid in Hawaii. Was the dark plastic bag touching the board? Those spots could easily have gotten way too hot and softened the resin until it let go in response to the rising pressure in the blank. You know what you did, but I see several possible culprits in your post. Tomorrow is another day. Chalk it up to experience. There are lots of great epoxy glassers here. Most of what they know is searchable. Study up before trying again or history repeats itself. If I can help in any way PM me.
I painted a board with a black deck inlay, and I guess the RR resin did not like the paint becuase after being in the sun one day the whole thing delammed where the board was painted… I would do like mentioned above and try to inject some resin under the glass and whey it down. Ive vented all my EPs boards at some point becuase they’ve been hit/dropped whatever and taken on tiny bits of water thats easier to get out with a vent