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| Home Made Boards (6188 Posts)
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Home Made Boards |
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edges
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On 10/23/2005 herbn
wrote in from
United States
(64.12.nnn.nnn)
I wait and see how my first balsa board holds up, it has two coats of epoxy on the edges but other than a sort of central ash stinger there is no hardwood in the edges. I keep thinking about making a reduced pattern,exactly like the boards final pattern but made smaller with modified trimming bit. The reduced pattern could be used before the board is cut to shape as pattern to cut a channel in what will eventually become the edge of the board. Pieces of hardwood that fit nicely in that channel could be mixed with a cup of epoxy and squeezed/layed into this channel,when the board is rough cut and trimmed ,it'll have a very tough edge.If the pieces are a bit small and enough epoxy is poured in the top of the channel would be all epoxy, kind of like what lib tech does.
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how is vertical/end grain balsa
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On 10/21/2005 duane
wrote in from
United States
(68.15.nnn.nnn)
in tension its useless, but I don't think it will be in tension. If you are filling pockets, and flex the board, the skins try to come closer together, so it is in compression (vertically). There may be slight tension in the transverse direction but so slight it won't matter, the carbon would shatter long before the balsa tore apart. You can take one of the sheets of end grain and make a 2 foot radius, thats far more bending than you'll see.
I wouldn't line the pockets, it isn't necessary, just use a bit of titebond glue to hold things in place and skin as usual. Continuity of the core is unimportant, it just needs to have no or small gaps, and lots of shear strength, to keep the carbon from folding. One of the skatecars we made had slitted foam along the entire length, it held 540 pounds amidships before breaking, tested when obsolete.
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svartelds project
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On 10/20/2005 herbn
wrote in from
United States
(64.12.nnn.nnn)
i'd be tempted to sandwich in some strips of that real thin birch multiply, into the i beams,just so the foam is even more a building aid and not at all relied upon as structural. Hey duane, how is vertical/end grain balsa, in tension? if i built up thick sections at the ends of a board and hollowed them out for pockets,if i pressed in carbon into and lining the pocket, running out a bit onto the bottom of the board there shouldn't be a problem.
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Hollow carbon core
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On 10/20/2005
svarteld
wrote in from
Sweden
(213.64.nnn.nnn)
Soon I'll be able to vacuum press my decks, and I have an idea of how to make the core, that I'd like to hear what you think about it.
Let's say you make the finished shape from light foam, maybe that blue 2 lb/cubic ft styrofoam, normally used for insulation, wich seems to be too weak for a foam core if you read previous posts, but easy for me to get hold of. Then cut the core in long slices along the length, from back to nose, top to bottom. Maybe 3-4 cm wide. Then epoxy them together again with double carbon weave between the cuts, folded out a little on the top and bottom, spreading them apart both ways on the surface, forming many "I-beams" of carbon along the deck inside the core, to divide the vacuum-epoxied skins of carbon. The edge gets a single similar piece of weave, folded inwards on the surface. I guess the foam mostly hold the I-beams upright, and takes some minor load between the beams? Guess that depends on the distance between the beams/the number of slices of foam.
A hollow carbon I-beam core with carbon skins that is, if you think of the foam mostly as an aid in building the structure.
I'm eager to make free 3D shapes that a block of foam will allow. I'll probably add some solid wood around the truck holes, with M5 inserts in the wood on the non-truck-side. the wood could be the same width as the foam slices, exchanging the foam for wood for about one truck length, two slices between each other to cover the truck width, with carbon I-beams around the wood slices, just like around the foam they replace.
Do you guys think this core might work? Difficult? Might 3-4 cm in between the beams be OK? Better ideas?
Thanks /P
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epoxy coating
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On 10/19/2005 herbn
wrote in from
United States
(64.12.nnn.nnn)
well i got the battery for the scale and mixed up a little 70 gram batch for a surface coat, i pressed the surface coat with some sheets of uhmw to try and get that pressed in effect,naturally the edges won't be pressed ,but it's a pretty thin coat ,but the little bit that squeezes out may stay on the edge. Ihad my 300+ lb friend stand on my barely 2 lb balsa/carbon+ 10plys of birch (.186) amazingly strong.
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black glue
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On 10/19/2005 duane
wrote in from
United States
(68.15.nnn.nnn)
is likely melamine based formaldehyde glue. heat-set or catalyzed most likely to speed up production. The stuff called Resourcinol is very similar, I think its purple and comes in two cans, but its been years since I used the stuff
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that multiply thing
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On 10/19/2005 herbn
wrote in from
United States
(205.188.nnn.nnn)
thinner layers of wood increase the amount of glue,glue has no grain or is actually brittle(like epoxy run off)boards with a lot of glue are heavy and generally not all that strong. Cutting ply into thin strips and gluing gvertical ply is a good example of this. Glue joint usually out last the wood, like wood will break right next to the glue,if you kept making the wood thinner and thinner and could get it very close to a single layer of uninterupted wood grain...things would be very good. The black glue of birch multiply seem to be relatively low density, that's a good question, what kind of glue is that? I found the second bottle of hardener that i forgot about(came with the order)i just need to buy a ninevolt for my scale i thought it used AA which i knew i had.
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herbns boards
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On 10/18/2005
Sean
wrote in from
United States
(167.206.nnn.nnn)
hey herbn, is all this work at your house? cause i was wondering, everybody keeps asking for pics of your work, and i come by skatewerks a good amount, if you wanted i could stop by with a camera one day and just document all the stuff and post it to show everybody... you could shoot me an email if u want, or just make a post on here sayin what u want...
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multi thin plys
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On 10/18/2005
Fitz
wrote in from
Australia
(203.201.nnn.nnn)
spot-on herbn. Ply, just like glass and carbon just gets stronger with the use of multiple cross directional layers. The best stuff I've found for wooden decks is the aircraft grade Finnish Birch. 0.4mm (or 0.015625" in your scale) each ply! Sand it too much and you're going straight through a layer. Unfortunately Its' not easy to get a hold of and costs the bomb aswell. I prefer the 3ply stuff and lay it down like its 1 skin.
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thin multiply
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On 10/17/2005 herbn
wrote in from
United States
(152.163.nnn.nnn)
well now i know what to do with the scraps. wait finger slalom boards! Actually that board ,with the 5 ply (.093 thick skins) Seems amazing , my scale is totally out of batterys and i'm out of hardener for my epoxy, so i'll have to wait on finnishing that board but i did trim it nicely,and it flexs just a bit more this board should be amazing. Thin multiply seems like it would be very evenly stong in all directions, i think of it as the wood version of the folded steel in a samori sword.
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Birch
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On 10/17/2005 thrash
wrote in from
United States
(64.174.nnn.nnn)
Man I take that previous post back Solid Wood Mancala. I think I f'd it up by using the wrong wood. Oh well it was my first attempt, I'll try again...thanks.
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Birch
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On 10/17/2005 thrash
wrote in from
United States
(64.174.nnn.nnn)
Nah, the baltic birch I used was the 5/8 inch 5x5 ft sheet. I used a polyurethane cement to glue together two of the sheets as well. So any recommendations on the suggestion of adding a layer or two of fiberglass on the board to strengthen it up?
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anybody know why such thin muti ply is made
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On 10/17/2005 duane
wrote in from
United States
(68.15.nnn.nnn)
it make bitchin' dollhouse furniture
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The birch you want is Baltic Birch ply
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On 10/17/2005
Greg Olsen
wrote in from
Canada
(206.172.nnn.nnn)
It comes in sheets 5' x 5' and will cost you about $40 per sheet. It sounds like you are using birch-surfaced ply. Chuck it out and start over.
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Too much flex
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On 10/17/2005 Solid Wood Mancala
wrote in from
United States
(24.185.nnn.nnn)
I think you're using the wrong plywood.
5/8 Birch multiply (the stuff you probably should have used)has 11 plys.
You stated on your website that both pieces together had 10 plys.
If you ARE using regular birch plywood (birch veneer plywood with a few layers in between of something that may not be and probably is'nt birch) that would explain the wimpiness of the deck.
(by the way, 2 layers of 5/8 Birch multiply would flex nicely IF you weighed about 400 lbs.)
I would'nt add fiberglass to it. There's no sense in putting any more time into something that's just not going to work very well.
Just my opinion.
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Longboard Deck too much flex
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On 10/16/2005 thrash
wrote in from
United States
(69.224.nnn.nnn)
Here's the board...
http://www.sk8club.blogspot.com/
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Longboard Deck too much Flex
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On 10/16/2005 thrash
wrote in from
United States
(69.224.nnn.nnn)
thanks man! yeah the 40.5 board is two 5/8 inch boards glued together. I pressed them and used polyurethane. So the board is as thick or thicker than other decks. I guess it's all trial and error until perfection comes...
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to flexy for my hills
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On 10/15/2005 herbn
wrote in from
United States
(64.12.nnn.nnn)
40.5 isn't all that long 5/8 should be thick enough although you may be heavier or have really high standards for stiffness. I'm also wondering what "gluing the sheets of 5/8 baltic birch together" means. You are apparently trying to make your own plywood,the lack of strength could be the glue you're using,is the "birch" really birch or is it 1/8 inch birch vineer paneling,in which case you're making a board out of compressed saw dust,mostly.
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Longboard Deck too much Flex
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On 10/15/2005
Thrash
wrote in from
United States
(69.224.nnn.nnn)
I just finished my first creation of pressing a longbaord that has 1/2 inch depth of concave and is 40.5 inches in length. I pressed and glude to sheets of 5/8 inch baltic birch together and after adding the trucks realized it has way too much flex. I'm trying to create a stiffer board for bombing and was considering adding a layer of fiberglass on the bottom...Any suggestions on stiffining the board up??
SK8KLUB Scott
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can't wait
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On 10/15/2005 herbn
wrote in from
United States
(205.188.nnn.nnn)
i did a close "rough cut" so my questionable trimmer bit should be fine,maybe i can wait til monday,maybe. As far as thinning epoxy... i looked at my posts, i'm typing so much faster now, than i used to, i break the posts up so if i get cut off or there is some other computer glichy thing i don't lose a long post.
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birch skins
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On 10/14/2005 herbn
wrote in from
United States
(152.163.nnn.nnn)
having carbon for that high tech punch/spring/boing out of turns and as a general ride, but keeping it minimal and having that nice dampening birch on the whole outside should give a nice natural plushness to the occasionally maligned carbon compositness. hhmmm?
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Those birch skins
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On 10/14/2005 herbn
wrote in from
United States
(152.163.nnn.nnn)
This board has birch skins over partial carbon skins, i think i see the carbon in one or two spots on the edge of the board but this was unintentional,i did not want fraying carbon on the outside of the board, glass would not have been better,and would have shown the pieced together carbon and any fraying, a plastic skin like a snowboard would be interesting ,but this 5 ply birch(only.093 thick!) looks so natural and nice it soaks up some epoxy,which may sorty of optimize the strength of the carbon, it certainly feels optimized. Does anybody know why such thin muti ply is made, i think its for skins on wooden planes and is probabely used extensively by model builders. I'm not gonna trim this board until i get a new trimming bit, the one i have has seen better days and made a few splinters in the last boards i made.
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balsa core board
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On 10/14/2005 herbn
wrote in from
United States
(152.163.nnn.nnn)
As i've mentioned previously,this board has a end grain balsa core, the grain runs from the top skin to the bottom. Is has a central ash stinger maybe a half inch wide and edge stingers that were there mostly so my edge gluing jig wouldn't be pressing on the balsa, only a couple inches of the edge stinger remains after the board is fully trimmed. I want drill rows of holes just inside the outline of the board and make little hardwood dowels to be epoxied in before the board is trimmed, but i'm gonna leave that for the next board. This one is gonna be light light.
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Holy balsa !!!!!!!!!!!!
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On 10/14/2005 herbn
wrote in from
United States
(152.163.nnn.nnn)
I just did the first trim cut on this board,WOW! looks like it'll end up 2-2.5lbs,it's .600 thick(15.24mm)It seems to have a very taut flex the out side of your feet can be 25 inches apart before they go over the wheel clearence cutouts. This is my mid shape,40 inches(101 cm) i lengthened the wheelbase on the first board of this shape by about 1.25 inches and i'll definitely do that here too.
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epoxicle
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On 10/13/2005 herbn
wrote in from
United States
(205.188.nnn.nnn)
ah yes! today's inspection show a nice solid blue chunk of e poxy with the mixing stick solidly encased. I'm still gonna wait another day, this should be interesting. I should put some purty walnut stingers in this board, there i go again,seemingly dodging a bullet and i go and make things more complicated,nah pure function.
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