anbody doing stringerless 1# or 2# eps with cloth and resin ? not balsa or d cell.
What kind of results ?
Length of board ?
Type of foam ?
Layers and weight of cloth ?
Greg L has been doing them for years (1.2 & 2 lb) with just glass and he’s very happy with them.
1 lb with no stringer ?
I saw in one of the the “Cerritos” pictures that the blank he was shaping had a stringer in it. Looked like eps. Was wondering if I should put a stringer in my next one. And just wondering what other swaylockers are doin and what success, without vac baggin, etc.
Dower:
I built a 5'10'' x 23'' x 2'' swallowtail using a stringerless 'homecheapo style' blank back in the spring. I glassed double 6 bottom and triple 6 deck. My laps are quite large... say 3 to 4 inches. Now, I did do a balsa wood inlay on the deck, but I simply glued it in with Elmers white glue and don't think it is particularly structural--mostly cosmetic and with a mind toard pressure ding prevention. Resin Research epoxy of course. Great stuff although my gloss coats don't turn out worth a damn. Sorry greg. Even after glove treatment, denatured bath, climate controlled room and drinking a pint of additive F before bedtime I still get the fisheye (even on clarkfoam). I digress. The board surfs great. Interesting flex pattern. I can feel it flex when I lay down on it! When up and riding it seems to have good flex return. Its fast smooth and lighter than conventional construction-even with the gloss and big ole birch D fins. I feel like the key to this sort of construction (at least flex wise) is big honkin' laps (as one thread put it). I suspect it has a 'perimeter stringer' sort of effect. Bottom line: I think you can get great results with this sort of construction, granted my board is short and incorporates balsa to a limited extent. Only bummer is the fear associated with leaving it in the car (I didn't vent).
The Stingray and the Leviathon are both stringerless. Granted they both utilize Carbon, but I am sure it’d work with the right lam schedule…
http://www.swaylocks.com/forum/gforum.cgi?post=197909;#197909
http://www.swaylocks.com/forum/gforum.cgi?post=220857;#220857
Hi theboys,
I would be interested in learning more about how you did the balsa wood inlay. A friend of mine has talked about doing one on his board.
Thanks,
Dave
yeah, i like that balsa deck idea. been thinkin about doin’ it on the deck only. mainly because the only tools i have are a sureform and sand paper. i have been tryin’ the vac bag on lams. not all that successfully.
Dave:
It’s pretty low tech and time consuming. Here goes:
- I taped off my desired insert area (which also happened to correspond to my lap line).
2.I laminated the bottom of the board using double 6 and tinted orange.
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I let the epoxy cure, then cut my laps with an exacto and then yanked the tape.
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Naturally, the double six lap leaves a ridge. Normally, I would press the lap down flush with the foam before glassing the deck. For the inlay, I simply left the lap as is.
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Starting at the nose, I placed a 4 inch strip of cheapo masking tape over the deck and laps. Using a small hobby knife, I cut the tape along the lap ridge, ultimately creating a tape triangle (shaped like the point where the laps meet). I took this triangle and stuck it on the end of a 4" x 36" strip of craft store 3/16th ‘’ balsa. I used the hobby knife to cut out the top two sides of the triange. The resulting triangle tipped strip of wood fit snuggly up against the laps in the nose.
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I spread a thin layer of elmers white glue on the balsa–it will begin to warp–don’t worry. I then placed the strip down the middle of the board at the nose and then “bagged” it using 3/4 inch blue 3m painters tape. I used a lot of tape. I let the glue dry for a while and removed the tape.
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I repeated this process, using the tape to create a “jig” for the balsa/lap juncture until I had the whole deck covered. You have to be careful in selecting your pieces and make sure the straight edges make nice smooth butt joints with one another. Otherwise you’ll get shitty looking gaps. Oh, don’t try to use wood putty to fill the gaps as it looks lame.
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Once the deck was completly covered flush to the lap, I used some 150 to feather the balsa/lap juncture completely smooth. This was necessary so the deck lam would come out real smooth. You will then need to use progressive grits to remove the resulting ugly cross grain scratches in the balsa.
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Lammed the deck with 3 layers of 6 oz. This might have been overkill but the resulting board is still really light, flexes nice, and is hard as a brick. Lamming the deck is super fun–seeing that wood grain emerge is great.
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Hot coat, sand, pinline (mine was dark green), gloss coat (grrrrrr!)
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Next time I think I’ll gloss with an automotive spray acrylic.
I hope this was comprehensible.
I’ve done lots of stringerless boards and with EPS and epoxy I loved the way they rode. With 2# density use double 4 on the bottom and triple four or double 6 on the deck. For 1# density use double 6 triple 6. Each of these constructions will be lighter and stronger than a standard poopie. To make stronger boards add more glass.
I think it is also important to note–
I wouldn't try the inlay thing with poopee construction, well at least the pee part. I talked to some guys around here who indicate they did this sort of thing back in the 70's with poly. Delam city evidently. EPS/Resin Research is perfect for this application. I've taken this board through the paces thus far and its held up great. My friends have tried punching the deck to create pressure dings to no avial. I was not very stoked about this, but it held up no problem.
attn. “theboys” did you seal the balsa before doing the top lam? I’ve always heard that balsa sucks the resin right out of the glass and you have to seal it with a brush or squeegee coat of resin before the lamination. You said nothing about this, so can we assume that in your case it wasn’t needed?
Also… 3/16" balsa?! Guess there was a lot of sanding at the lap line to get it to match the thickness of the bottom lap…? Why such thick balsa? I’d have though to use 1/16 or 1/8, and it would have been cheaper too.
Hey Honolulu:
Good call on the 3/16th bit. I typed that mistakenly. I used the 1/16 thick stuff. Any thicker and I think it would’ve been difficult to “bag” the wood to conform to the compound curves–I did a bit of concave in the deck. Even with the 1/16 there was still a bit of sanding to be done at the lap. Please excuse the mistatement.
Additionally, I did not seal the balsa prior to the lam. This didn’t seem to create any problems. I’ve done two like this and both seemed to require resin quantities within the parameters Greg has outlined elsewhere. Further, I only had slow hardener at the time and the temperature conditions were less than ideal (pretty low). I think this worked out well as the resin had an opportunity to seep down in the little crack and joints between the wood.
Also, the bottom lap (folding over from the deck lam) included all three layers of 6 oz, i.e. all cloth layers lapped about 3 or 4 inches rather than cutting some off around the rail. This was a big pain to wet out, but I think it contributes positively to the board’s flex pattern.