well that is starting to explain things then…coz i did claim they were more crispy and had a harder feel ,
also ive been working lately with adding toluene and a few other things to my epoxy…the more solvents in there the more flex and rubbery feel you get …so cooking normal epoxy resin surely would release some amounts of solvent or whatever else is in it to make it more flexy…
thus giving a harder crispier lighter board…
yea tom what i meant by a closed system ,
the job was set up with no facilities for bleeding off excess resin,the resin that was put on the board wet couldnt go anywhere ,except for vapour out the vacumn pump…
as far as the comment about temperature yea we were pushing 85 degrees celsius , hotter than that and things would melt …
but if your vacumning and baking p/u yea 65 is the limit coz you hit the foams hdt…ive made enough dried prunes to have worked that one out…
This is off topic I realize but while I have the epoxy pros here, I’m going to ask…
My girlfriend bought a glass hummingbird feeder. It’s shaped like a light bulb and has a rubber stopper and feeder tube at the bottom. We discovered a crack and since she liked it, I thought I’d seal the crack from the inside by smearing a coat of epoxy over the crack.
After it cured, we filled it with the standard red food color in sugar water and hung it outside.
About a week or so later, it was leaking from the crack. I took out the stopper and the epoxy was peeling off. More interestingly, it had turned red from the sugar water and was very flexible. I still have the piece of epoxy (it’s been over a month) and it’s still rubbery and flexible but still very tough… I can tear it but it’s pretty strong.
I know this has nothing to do with surfboards but thought it was pretty interesting. I’d be happy to send the sample if someone wants to see it.
I'm only guessing here. But, it sounds like it did not kick completely. The mix ratio may have been off. It also sounds like you may need to rough up the surface to get it to adhere. Some plastics are very chemically resistive and are tough to get a good bond on. Also, the epoxy will absorb the die from the water because it's porous. You may have better luck with cyanoacrylate (Crazy Glue).
Yeah, Toms right, superglue is excellent, and you can get it in large bottles and three thicknesses, with an accelerator spray too. Most shater dings can be very successfully fixed with superglue, leaving virtually no trace.
And Bert, is there a reason you don’t use a bleeder ply in your vacuuming set-up?
I know this sounds weird… the epoxy was fully cured before we filled the feeder with colored sugar water. It (epoxy) seemed to absorb the red sugar solution (it looks red all the way through) and turned flexible after having cured to a rock hard state. I wasn’t really looking for an answer to the bird feeder problem - just thought the epoxy morph was weird and kind of interesting.
Bert, Fair enough. Commonly available info is good to spread around, but personal techniques and innovations should be a closely guarded advantage. I’ve been through that also, and what eventually leaked out got misenterpreted, wrongly done, and then ended up getting bad mouthed.
John, as Tom said earlier, epoxy remains porous, even cured. Not so critical on boards, as they only visit the water, and get a chance to dry out frequently. Boats, fuel tanks and the like must be coated or painted with something to make them watertight.
And Bert, is there a reason you don't use a bleeder ply in your vacuuming set-up?
I’m not Bert, but I have a lot of experience with composites and vacuum bagging.
One reason not to use a bleeder/breather ply is finish. If you dial in the right amount of resin on your laminate, and you use a release film only, you will not have to do a hot coat. Except for a little sanding here and there, your board is done. And the finish is as smooth as glass.
Experience from trial and error will give you the right resin saturation. Too little, and you won’t have enough resin to fill in the weave. Too much, and your board is heavier than necessary.
By the way, if anyone is interested, I received all my composite fabrication training from Cerritos College here is Southern California. They offer some of the best composite training in California, and they are the only ones offering classes in Southern California. They do the training for Lockheed. But the best part of it is they let you use all the materials you want for your projects at no cost. In addition to fiberglass, they have carbon, kevlar, and even pregpregs. They have all kinds of bagging film, release film, breathers, bleeders, etc, for vacuum bagging. They even have an autoclave. The department head is pretty cool, if you don’t want to take a class, you can just sign up for a lab class and work on your own projects. If anyone wants to know more, let me know.
I agree Kenz, and I think the main reason the surfboard industry may take a long time to adapt to this technology, if ever, is because of this industries need for the necessary skilled, and technically trained operators. Good to hear you are getting some of that. Putting in many years of practical experience goes a long way too.
And Bert, is there a reason you don’t use a bleeder ply in your vacuuming set-up?
I’m not Bert, but I have a lot of experience with composites and vacuum bagging.
One reason not to use a bleeder/breather ply is finish. If you dial in the right amount of resin on your laminate, and you use a release film only, you will not have to do a hot coat. Except for a little sanding here and there, your board is done. And the finish is as smooth as glass.
Experience from trial and error will give you the right resin saturation. Too little, and you won’t have enough resin to fill in the weave. Too much, and your board is heavier than necessary.
By the way, if anyone is interested, I received all my composite fabrication training from Cerritos College here is Southern California. They offer some of the best composite training in California, and they are the only ones offering classes in Southern California. They do the training for Lockheed. But the best part of it is they let you use all the materials you want for your projects at no cost. In addition to fiberglass, they have carbon, kevlar, and even pregpregs. They have all kinds of bagging film, release film, breathers, bleeders, etc, for vacuum bagging. They even have an autoclave. The department head is pretty cool, if you don’t want to take a class, you can just sign up for a lab class and work on your own projects. If anyone wants to know more, let me know.
How much do those classes cost and how long are those classes?
The classes are at night starting at 6:00pm, usually going until 10:00pm. They have a few classes on Saturdays. It’s a junior college, so it costs $18 per unit. Most courses are 3 units. I just signed up for a lab class this semester and it’s .5 units, so it cost me only $9. Can’t beat that! I’ve taken all the classes, so if you have any questions about certain classes, let me know. Here is their web site with course descriptions:
thats awsome …anyone who takes that coarse is gonna save themselves a lot of pain…
plus be introduced to some pretty kool stuff …
the future in surfboards is there…
call it a hunch or a prophecy …but when you can build surfboards 30 to 50% lighter and they out last 20 normal boards ,then i would say thats what people wanna build …
funny enough the most interest i get from crew who wanna build the style of boards i do, is all from young up and coming kids getting into the industry …
most of the established guys already have a daily routine of doing p/u and just put it in the to hard basket…
i remember this young couple who came into my shop once ,a young shaper and his girlfriend asking alot of questions …and advice…
i remember the chick saying “were young we wanna learn about whats new not whats old” then the young guy backed it up with the comment"i could learn to build weak heavy boards or these light strong ones, which would you pick"
i sent them away with enough information to fry there brains…woulda taken at least 2 years to put it all together…
but seriously theres alot of questions i dont mind answering without feeling threatened ,coz ive been established for a long time ,had results ,got a good team of surfers ,so no one can undo that…