In the pic it looks like the area where the rail saver pulls on the tail which would make some sense. Is that the only area this is happening? Any other pics would really help.
Yikes! That happened to me once and affected two boards (now trash) and some fins. I nver did figure out what it was. I do have a question for you- what are you using for color there? I used some acylic paint on the boards that delammed. I had separation of layers that were not in contact with paint but if you tell me you used acrylic I’m going to be suspicious.
why does it take you 3 days to do what the low Tech Lab does in less than 24 hours. Think about chemical bond......Plan the next job......seperation should never be an issue.
After having entered the surfboard building industry around about 1969 when i were only a youngster windswell allow me to give you some sound advice. … Firstly, certainly you should explore the wonders of modern resins but these items should rightly be relegated to the pages of the past. Today in 2013 the chemistry is moved on. We no longer need Poly-Ester nor Epoxy in a world where Poly-urethane blanks are forbidden under EPA regulations in the State of California which is a long way from here in Queensland Australia. Still, you’d have to be a dimwit to not realize PU is a blight and it is well we are done with it.
Likewise the use of Polyester is out there and out-dated as a resin. There are some serious and effective alternatives to all the above. The chemistry as of 2013 is a dynamic that if you will explore it, will blow your mind.
No surfboard or marine epoxy is totally non blush (a reason I never make that claim) it can’t be. You get up into high humidity, especially if it’s cool, and there will be plenty of blush for this to happen. Additive F in the laminate eliminates the blush chemically or you have to remove it physically (sanding). Chemical wipe downs or soap and water washes will help but not guarentee success.
Quanta, tech is moving all of us along constantly, such incredibly varieties of build options today. Fun stuff tech, and some nice looking work there.
Hi, slightly off topic but I have a question about additive f. If the surfacing agent is some kind of wax dissolved in a solvent, doesn’t that mean that any time you use additive f in a laminate there will be some wax left on the surface?
I have heard amine blush described as a “waxy residue” not the same kind of wax as the surfacing agent, right?
Is it the case that when you use additive f in the subsequent fill coats it re-disolves any surface wax residue and pushes it to the new surface?
here in Florida in the hot weather I sometimes have a hard time having enought time to brush out my fill coats very smooth, especially with kwick kick but sometimes with 2000 resin and fast hardener. It appears to me that the additive f is sort of bubbling out of the film as I am applying it.
do I just need to use more additive f? I’ve tried double. How much is too much considering it is very warm and humid here?
Blush isn’t a wax it’s a bi carbonate the develops as a reaction between the curing agent amine and moisture and oxygen in the air. Additive F has solids which come to the surface and seal allowing a full cure at the top of the resin and at the same time eliminates that air/resin interface. At full cure you now have a good bonding surface and/or a nice surface to sand.
Additive F is a surfacing agent and although different in chemical make up from polyester wax solution, it essentailly does the same thing, seals the resin surface. A big difference though is that in polyester resin wax solution with inhibit bonding while Additive F in epoxy will enhance bond. The primary reason for this is that nothing in the epoxy world will inhibit bonding of successive layers quite like amine blush. Because surface blush is a pre reaction of amine and moisture there is no way that the next coat can disolve it. Even washing will many times leave enough blush behind to give you problems. The other reason for this Additive F enhanced bond is that epoxy is a very aggressive bonding agent and will dissolve right through the Add F solids left on the first coat surface.
As for heat when using Additive F, when it gets very warm there is less time for a surfacing agent to surface so you have to use more. This is true with any thermoset surfacing agent whether your talking epoxy, polyester or PU resins. I’ve even tripled the amount in mid summer.
You should be able to get your hot coats on no matter what temperature your working. You need to flow the hot coat on with the brush instead of trying to brush it like paint. Pour the resin down the middle and with firm pressure snowplow it to the rail. Go to the opposite side and repeat. Then with medium pressure do a quick end to end cross brushing followed by a light pressure lengthwise pass. Hot coats done this way take 3-4 minutes to apply and will ensure you dissolve those surface solids giving you a fisheye free perfect flat surface. Done this way without wiping, washing, or any other tricks you’ll get perfect hot coats 99.9 percent of the time.
I've had the exact same thing happen. I take blame though for using epoxy resin in temperatures below the manufacturers recommendations. It was humid as well. It was also on a very expensive multi-stringer longboard blank(!)
My solution is the "Lam-Fill-No Flip" method. It was recommended to me by Benny Sparks (Benny1), a dedicated self taught comp-sand guy and Leslie from Fatty Fiberglass, who learned from Clyde Betty in Santa Barbara.
Laminate as normal but as soon as the epoxy has cured to the point that you can apply some masking tape, tape off an apron and fillcoat it. When cured, scuff the overlap area on both sides before you laminate/fill coat the other side the same way. You can either scuff the remaining overlap on the bottom and fillcoat just the overlap area or feather the overlap as-is while sanding the bottom. If cosmetics are a concern, you will still need a sealer coat of your choice... another epoxy coat, poly gloss or acrylic clear coat. That will make any exposed glass left over from sanding less noticeable.
