steve,
Thank you for the information. If I do an EPS board, the properties you’ve described, are exactly what I would want.
welcome balzac,
Im quoting you here…first you said this:
What really makes the difference is the “pack and fusion” of the beads.
Then you said this:
I have a competitor that makes blanks in shape molds and does a nice job of it. However, when the blanks are planed they have a completely different feel to them because of the different bead size, pack and fusion. In short, just because they start out with a smooth finish is no indication of the pack and fusion. I started out thinking that the shape mold process would be the best way to make EPS blanks. I changed my view after we got down the road a bit and decided that the advantages of the billet molded and hot wire cut unit is a better and infinitely more versatile way to make these puppies.
Im confused. Isnt fusion to a large extent, a function of the size fo the mold? Arent smaller molds “better” in this respect?
I ask b/c it is my understanding that it is the large size of billet molds that create fusion problems b/c the beads at the core or guts of the billet get choked off (the critical heat/steam) by the earlier fused perimeter. It would seemt that a smaller mold (pressure molded blank) would eliminate this problem. But you are suggesting otherwise.
Whats the deal?
No expert here but an eps guy did tell me some basics a while back. Density is directly related to how many beads, or the mass of the beads, that you put into the mold. More beads, more dense, less beads, less dense because however many beads they’ll expand to fill the mold. He also said fusion has more to do with, and I’m a little foggy here, time under pressure. In other words, if the foam maker leaves the expanded beads in the molds under pressure longer they become more fused. A classic example of quality versus production. Pop 'em out quick and you get more production but poor fusion.
I know from the construction side of the EPS world they’ve got those billets figured out. They cut all sort of shapes out of billets and they seem pretty uniform.
Again, I’m no expert. This is just what I’ve picked-up.
If your company is the one that now supplies the EPS for ProCam, your foam has made a profound improvement from what they were using originally when they first started milling EPS about almost a year ago. The finish sand quality that I can achieve with these blanks is like night and day compared to the stuff they where using before. The problems we had with the old EPS they used are gone.
Problems such as:
Gassing.
Unexpanded beads (that are like little rocks) that get caught in your sanding screen/paper and scratch up the blank really bad when fine sanding.
Beads pulling off when shaping/sanding.
Beads pulling up when removing masking tape when painting.
All that’s pretty much history now thanks to your foam. I probably have finished sanded and painted about 600+ of these blanks so far and the consistency has been great.
I understand yor confusion. It does seem that logic would dictate that the smaller mold would produce the more packed and fused product. However, this hasn’t proved to be the case thus far in the EPS foams available here in California. That is why I changed my mind about shape molding vs. the billet molding process. Since we have been able to produce an EPS that has become such a favorite of so many shapers I haven’t really given a whole lot thought of heading back to the shape molding process.
Ryan brings up a good point in the post right after yours about the rest of the molding process (heat, pressure and time) also being reasons for improving the pack and fusion qualities of EPS. It’s quite an involved process making the stuff and each step in the process along with the raw materials used is critical to the quality. It takes us a lot longer to make our surf specific EPS than it does our construction grade stuff.
Steve
Atomized,
Thanks dude. You have no idea how hard we worked to get this stuff where it is now. The guys at Procam have been a huge help with feed back and encouragement.
Mahalo Brah
Is anyone here in Hawaii selling your foam?
Quote:
It does seem that logic would dictate that the smaller mold would produce the more packed and fused product. However, this hasn’t proved to be the case thus far in the EPS foams available here in California.
Are you suggesting that Marko is not well packed and fused? Its one thing to say that you (your company) can pack and fuse a large billet really well. Its quite another to say that others, using a different approach, are not. There IS a difference.
I have not found a means to get it there at a reasonable cost as yet. Sorry.
Iv’e also used Marko blanks and their EPS is also an excellent foam. The only disadvantage to their molded blanks is the same with molded polyurethane blanks. That being that you are limited to blank sizes and rockers that are avialable from their molds. That will probably improve in time as more molds are created and there is more of a variety available.
cbalzac, how could I get your foam in SoCal? what brands is it sold under? Is it available by the block or only as finished blanks? What weights are available? Where could I see a sample?
Marko has done a great job at promoting EPS in the surf industry and they are really great people on top of that! I really like having these guys as a major competitor because they are really helping to push the quality and performance of the product. They are the only group I know of besides us that actually manufactures the EPS that they use. That means we have the means to control what kind of foam we make and be able to really experiment with any new technology that comes from the EPS bead and equipment companies. Everyone else has to take what the huge producers like Insulfoam churn out and take their chances with the outcome.
My experiences with Insulfoam weren’t good ones. That stuff is awful. If you do a search on my early posts since I first joined Sways you’ll sense some of the fustration I was having with it.
Hi cbalzac -
I had a chance to meet with Ken from Segway Composites recently. He said he asks for a specific process when Insulfoam makes his billets. It provides a different product than what they typically sell for insulation or architectural applications.
A custom blank I recently received through Segway IS different from a stock EPS foam billet I bought from Insulfoam via Home Depot. The process he specifies seems to work… I haven’t found a loose bead yet.
Ken is also a great guy to work with. When I asked for a specific rocker tweak, that’s exactly what he did - no problem.
FWIW, just my .02 based on actual experience… nothing to do with current Segway ads running on Swaylocks. I’m out of the loop on all that.
cbalzac,
Can we get your billets here in Texas at a reasonable shipping rate?
My limited epoxy experience…
I have found that different resins absorb at different rates on the 2# foam. I generally seal all the 2# blanks…
I use a mixture of DAP, extra microballons and a squirt of acryllic for the mixture. this leaves a nice, crunchy finish to sand . I use this primarily for a paintable surface. The absorbtion properties of the foam are readily apparent when setting boxes using resin…LOL without microballoons in the mix, the resin soaks through to the deck leaving those nice little vents in the futures open…
I think a little absorbtion is good …makes for a strong surface…
And I have never tried laying cloth on a whetted surface…sounds like a nightmare to me…
A “wet” lam is one where all the resin has not been pulled from the cloth weave. …a “dry” lam will be …well DRY! A sucky blank will suck the resin from the cloth before it gells leaving dry spots that will gas like mt st Helens when trying to seal coat…not good.
Just my limited experience…
CBALZAC…let me know about the foam when you get a chance…
Krokus
Hey Steve:
I think I’ll jump in here again and explain a few of the technicals if
you don’t mind. (You prob. don’t want to scare off the newbies)
Pack refers to the number of beads blown into a mold before fusion
by air thru guns called “fill guns” (duh) In large blocks and complex
custom shapes (such as the nose of a board blank) this can be a
problem depending on the placement of the guns in the machine/mold.
Fewer beads means a density change from the closer areas to the gun
to areas further away. Gun placement in custom molding is as much
an art as a science.
Fusion is the melting of one bead to another. Steam shooting into the
mold does two things, it softens up the skin of the bead so the plastic
can fuse together, and expand the bead so it pushes up against its
neighbors. When you break a piece of EPS, you look at the number of
beads that tear thru the bead vrs. the number of beads that seperate
at their bead to bead interface.
Too much science/engineering for ya? Go have a surf and come
back to read some mo’!!! LOL
Gettin’ ready for a big surf New Year!! Look out Bill, Keith, George it’s
headed your way too!
BKB
Surfteach, thanks. Very interesting explaination.
Now we just need to find someone on the east coast who makes the good stuff too.
what company do you work for and how would one obtain this surfboard specific eps?