Thread: Engineering/laminating question.

3/4" is to big for your application as spring back will be a constant issue. To force the stock to accept the curve, it will have to be ripped into thinner pieces.

I can't address your strength and stiffness requirements without and understanding of load paths, but generally many thin laminates are far superior then a few large ones. On the other hand, if your solid stock could be steamed or other wise bent and held the curve desired, your laminate schedule has possibilities. The key would testing the deflection rate under a specific load and compare this to the laminated beams.

Originally Posted by PAR

3/4" is to big for your application as spring back will be a constant issue. To force the stock to accept the curve, it will have to be ripped into thinner pieces.

I can't address your strength and stiffness requirements without and understanding of load paths, but generally many thin laminates are far superior then a few large ones. On the other hand, if your solid stock could be steamed or other wise bent and held the curve desired, your laminate schedule has possibilities. The key would testing the deflection rate under a specific load and compare this to the laminated beams.

I was afraid of that. I'd rather use the thinner lams...what to do, what to do...

I've used this trick before, working in the field on repairs. Make a thin plywood foot for your jig saw and screw it to the foot of your saw. The blade should just have enough room to clear (make a slot or hole). Now clamp the jig saw upside down in a vise and presto a Mickey Mouse band saw. Yep, watch your fingers, because they cut as easily as anything you'll feed into this contraption. You can rig up some blade guides with screws mounted above the work surface on a block of wood. With guides, the blade will not flex too much and you can make a fence. You can also do the same thing with a circular saw, though if you screw up, it will surely be a trip to the emergency room, hopefully without a body part on ice, in a plastic bag, stapled to your shirt (I've had to do this with other people's fingers). The circular saw has the advantage of no blade wander, but is clearly more dangerous, but in a pinch, a workable arrangement.

The ama (outrigger float ) has a net buoyancy of about 270 lbs, a dead weight of 30 lbs and is located 7 1/2' from centerline of main hull. Sail area is 84 sq. ft, max displacement is around 700 lbs.

http://homepages.paradise.net.nz/gar...ackingSail.pdf

I located some reversible base molding of the proper thickness. Inner lams are pine, outer lams are red oak. I have one laid up on the form right now. I'll probably cover the outer lam with a layer of cloth. It's not my ideal selection in wood, but it's what I can get without spending WAY too much money. As it is, the 14 lams cost me 250 American frogskins, to have the wood custom cut would be at least twice that amount.

The most reliable and strongest wood on the outside of course.
MIK

Originally Posted by Boatmik

The most reliable and strongest wood on the outside of course.
MIK

Of course!

For that kind of money, you could buy a cheap, maybe a used table saw and rip some stock to the dimensions you need.

Originally Posted by PAR

For that kind of money, you could buy a cheap, maybe a used table saw and rip some stock to the dimensions you need.

I have a table saw, but getting it to handle 3" thick fir is real iffy. Not only that, but all the fir I have, and I have about 1500 BF, is 3/4" stock. It's pretty tough to get an accurate slice off of it.

Build a tall fence and flip the stock to get all the way through. A 10" saw will usually cut through 2.375" to 2.5" stock on a single pass. Flip it and you knock off the remaining bit. Of course this requires a truly square fence.

Originally Posted by PAR

Build a tall fence and flip the stock to get all the way through. A 10" saw will usually cut through 2.375" to 2.5" stock on a single pass. Flip it and you knock off the remaining bit. Of course this requires a truly square fence.

Maybe when I upgrade to a better table saw. Mine's old 'n rickety. Nevertheless, I popped the first beam blank off the form a couple hours ago. It looks much better than I anticipated.

Originally Posted by Rick_Tatum

Maybe when I upgrade to a better table saw. Mine's old 'n rickety. Nevertheless, I popped the first beam blank off the form a couple hours ago. It looks much better than I anticipated.

I have some pics of a beam up on my other thread on the building forum.

Believe it or not, I'm still alive.


Been shut down building for the last 2 years fighting with the homeowner's association over the use of my garage as a workshop, but things have changed and it looks like I'll be tooling back up

?????!!!
what sort of place are you living in?
could understand it here in a strata title block of units or similar.
and even then, provided it wasn't noisy, or a business,
or the title & strata constitution didn't specifically prohibit workshops,
the strata management would be on shaky ground trying to block it.
a 'home-owner assoc" implies detached dwellings, each on its own land.
Which environment is your reality Rick?
AJ
in Adelaide Sth Oz.