Its easy to find or make PU blocks like EPS??Then we can do the same process like EPS to make some blanks!!
I think that it’ll be a good option for the polyester adicts…
Did any one had tryed that??
Thank you all
Sorry about my englis…
From portugal
i don’t know if PU blocks exist, i’m sure they do somwhere. but the problem with it is you can’t hotwire cut PU because the fumes released would be VERY unhealthy. correct me if i’m wrong anyone…
i guess you could cut PU some other way similar to EPS, maybe with a long blade type of tool set up the same way as a hotwire…but i haven’t seen that done.
they use a fast wire , its an abrasive wire like a bandsaw …
major wastage …
regards
BERT
Yes i was thinking of using that kind of abrasive wire,but i cant find the PU blocks and if i find i dont know if that is a good option to make surfboards!
Any one had tryed that??Any problem??
thank you
I heard that when you use PU foam as a liquid mix, you put the two together and it blows into foam. TO get it dense enough for surfboard use, you have to use a mold to contain it … .
Dave sweet and clark both realized this and both made molds for PU . . .
Maybe use a rectangular container to hold it . . . Also Rich Harbour says the more you skin from the outside of the blank, the weaker it gets. Like the blank is strongerest on the outside and the more you strip and deeper you go, more weak the foam is. Could be another reason not to use blocks because the boards made from the middle would be light, but weak. . .
you CAN get regular Poly foam in blocks only problem is naturally i beleive it comes in a brown color light brown like the expandable foam you can spray from the cans, identical color, 8x4x6 sheets were like 80.00 last year.
This is just what I have seen, there may be some white out there. However if you have access to a cutter, cnc machine it wouldnt matter anyway
realistically 80.00 for 2 8 foot blanks isnt bad. The foam comes in grades just like eps and from what im told is pretty consistent
My idea is to make a mold that have rocker like a rocker table and approximately the disired thiknes but no shape at all,justa a rectangle with rocker.
Then mix the 2 componentes PU (a litlle more volume than the mold so it increases the density of the foam) and spread it all over the mold and seal the mold.
And then after the “blank” its done i just need to cut it in 2 parts and glue the stringer!
About the brown color of the PU i was thinking in laminate it with pigment!
I dont know if this is viable in terms of resistence and price…
If you go to the arts and crafts section of Wal-mart, or go to Michael’s crafts, you’ll find green PU blocks (not for surfboards), but for plants, mostly silk flowers.
The problem with PU blocks is the density is consistent throughout the block. Believe it or not, you don’t want this. One of the few great attributes of clark blanks was their varied density, with the highest density on the rails and at the nose and tail. Weight at the perimeter of the blank give the board a different feel.
You could compensate for this using the PU block foam by gluing together pieces of foam of higher density where you need it, and lower density foam where you don’t.
…yes, there re PU blocks…no problem with the hardshell, cause they dont have one… so they have the same density in all the block…but the “strength to weight ratio” thing is gone in that way…poor quality foam, not good for boards (proffesional quality)…
Its funny. A year & a half ago, I went to Home Depot & bought my EPS panels which bacame the “$14 Blank” board. At the time, there wasn’t a lot of discussion about EPS…but during that visit to HD, I also checked out the PU insulation panels. They are pretty brown, but they come up to 4" thick in my area, so no gluing would be necessary…
Since the Clark thing, everyone’s talking about EPS now. I’ve been considering - just to be a contrarian - going back to HD & picking up a PU insulation panel. Make a board, glass it with UV poly, post it up. I don’t know if it would be any good, but I didn’t know if the $143 would be any good either (it wasn’t - but it took me places which are).