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geoffreylevens · Joined: 18 Nov 2009 Posts:

Surf engine not working for me on this site lately so... anyone w/ experience gluing rocker into stack of plywood (rocker table type thing) I have just shy of 1/4 inch hardwood plywood. Am going to glue either 2 or 3 layers together (haven't decided yet) in rocker press. Any idea how much of the rocker I bend in I will lose when the wood comes out of the press? That would be a good thing to know!

Thanky

mrmike · Joined: 06 Sep 2007 Posts: Location: coronado, ca

glue blocks of hardwood about 1 1/2" thick 3" wide across the nose you could use ply wood but you can find lots of scrap hard wood at your local lumber yard. dish out the top with a body grinder then on the bottom use a belt sander this will give you a 1 1/2" dish in your nose thinner wood = less dish note: don't let it get to thin on top easy to do with the body grinder go slow!!! Cool

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geoffreylevens · Joined: 18 Nov 2009 Posts:

Mike, that's another option but I am also molding double concaves into the tail end at the same time. I am pretty sure I will lose some of that curve as well. Trying to get an idea of how much I will lose. This is definitely going to be a molded rather than a ground out job.

geoffreylevens · Joined: 18 Nov 2009 Posts:

Called local woodworking supplies shop and asked them. They said undoubtedly would lose a little but not much. Reckon I will just set it where I want it and go with what I get.

kage · Posted: Thu Jan 06, 2011 1:31 pm Post subject:

Probably the least experience wood worker on this site, but I lost about a half of the nose rocker I put in a plywood board. But I also glassed that board, which at the time seemed to make it worse. So a quarter from the wood releasing and another quarter from the tension of the glass? But you are laying up multiple plies, which I would (think) be stronger?
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geoffreylevens · Joined: 18 Nov 2009 Posts:

I'm hoping that's what will hold the rocker, 2 sheets of 5 mm hardwood plywood, Weldwood Plastic Resin Glue between.

Had that glue laying around for several years. Still good! Also some old RR epoxy I just tested and it is still good as well. 4 oz cloth likely to cover as if this works it will be a travel/airline board and likely get some dry land abuse.

Poobah · Posted: Sat Jan 08, 2011 2:39 pm Post subject:

This might help:

http://www.joewoodworker.com/veneering/vacuumforming.htm

geoffreylevens · Joined: 18 Nov 2009 Posts:

Thank you, that does have good info. I was going to only have two layers (so called 1/4 inch ply, really 5mm) but according to that article, you lose too much of your bend w/ only two layers and a third, even if veneer, will help hold shape. I would imagine a layer of fiberglass on outside will help hold it but it has to stay bent until that stage is done.

surffoils · Posted: Wed Jan 12, 2011 4:05 am Post subject:

Hey Geoff, a 2 layer laminate doesnt hold its shape, you have to make it at least a 3 ply.
Im doing a 6 foot board at the moment and Im trying to keep it only 15mm thick, Im doing a lot of THIN layers to reinforce the shape.. XPS/ .6mm veneer/ 76 g Innegra / 4 oz glass / epoxy. About 7 layers in all.
Its a bitch to build up the layers over and over but the many layers appear to keep it solid.

geoffreylevens · Joined: 18 Nov 2009 Posts:

Thanks Sufrfoils, got that info from local woodworking supply shop as well so used 3 layers of 1/8" hardboard.

surffoils · Posted: Wed Jan 12, 2011 2:37 pm Post subject:

The only problem is that every layer makes it heavier and heavier, Im using XPS foam for the main core but after reading your posts Im keen to have a go with ply.
One thing Ive learned is to give it low rocker at the start because when it flexes it adds rocker and if you start with lots of rocker it can bend in the surf into a massive curve and bog. Or thats what happened to me !!
And then I tried to flatten the rocker out with extra laminates and it all went 'pear shaped' and I screwed the whole board. :oops:

geoffreylevens · Joined: 18 Nov 2009 Posts:

You can try (I don't know if it would work) on the over flexed to too much rocker, holding it/bending it back flatter w/ hand and arm force? Didn't the orig Boogie boards have tons of very soft flex?

geoffreylevens · Joined: 18 Nov 2009 Posts:

You can try (I don't know if it would work) on the over flexed to too much rocker, holding it/bending it back flatter w/ hand and arm force? Didn't the orig Boogie boards have tons of very soft flex?

The wood I am using is called "hard board" and though it looks to have super thin skin on one side, really only has grain going one direction. I think, too late for this one, having all grain run long ways down board will stiffen the flex you are finding problematic and give more torsional flex which can be good if the proper amount and won't cause much drag regardless

surffoils · Posted: Thu Jan 13, 2011 12:17 am Post subject:

thankd for the tips, are you soaking or steaming the ply first or just glue and clamp ?? Anyone done it with steaming box or similar ?

geoffreylevens · Joined: 18 Nov 2009 Posts:

No water involved (except in mixing up the glue) which I think is why there was the stress line/cracking noise in the cross grain bent piece. Aside from that, I think having all grain running length of board might give much superior flex characteristics. Doing that though would weaken it a bit as shown by occasional length wise splits in alaia type boards. Glassing w/ single 4oz I think would more than cover for that.