Best wood for laminating forms?

Re: Best wood for laminating forms?

William Duffield, on the Cohansey

>The best is probably not wood, it is MDF, but I usually don't bother to go for the extra expense and use whatever I have on hand, either scraps of 3/4" plywood or even tulip poplar. Tulip poplar makes sense because it is stable, cheap, widely available and easy to work.

Here are a couple of photos of a lamination form I recently built to construct a replacement for the stem end of a keel of an old wooden sailboat I'm restoring. The first photo shows four 3/16" white cedar laminations in the form while the epoxy sets.

The second photo shows the completed lamination, which still must be scarfed, tapered, cambered and rabbeted to fit the new garboards, and attached to the existing keel and nose block.

The form is scrap plywood. The money is better spent on what you are building with it, in this case the clear white cedar planks.

Re: Best wood for laminating forms?

Dan Fisher

>I have used MDF to make the forms. It is stable and easy to shape. The forms need to be treated to avoid glueing the lamination to the form. Wax -- effective, but it needs frequent renewal/reapplication. Plastic packaging tape -- probably a better choice.

The forms can be made in layers by shaping the 1st layer to final shape and using a router to shape subsequent layers.

The need for male/female or double-sided molds is a function of the complexity of the shape and also the number of clamps available. The glue up requires good pressure over the total lamination. The use of 2 molds helps reduce the number of clamps. Fewer clamps needed also meansa somewhat faster glue up.

Urea resorceinal(sp?) glue is probably the best choice -- waterproof and long open time. UR glue also reduces the amount of springback.

Re: Best wood for laminating forms?

Don Henthorn

>I agree that mdf is probably the most stable. I used male and female forms to laminate archery recurve bows. The parts were placed on the female part and the male form was bolted to the female form using strap metal bars. Pressure was applied by a length of fire hose enclosing a bicycle tube clamped at the ends where it had been cut. The assembly went between the laminations and the male form. I used a strip of metal as a caul to even out the pressure (probably wasn't necessary) and pumped the assembly up to 60 lbs. Worked great for the many bows I made.

MDF and vac bag

Bob Hackett

>

Re: Best wood for laminating forms?

MikeW

>Go to Roarockit.com and look at the videos. It's also a good product by the way.

They use dense building foam, a stiff bottom board and the vacuume press. Fastest/easiest way to build a deck form there is.

They sell skateboard kits as well.

MikeW

Re: Best wood for laminating forms? *LINK*

woodnfool

>If you are using a vacuum bag to build laminated forms the cheapest way to build a mold is using high density foam. The pink stuff that you can buy at Home Depot for insulating walls works great.

The video at Roarockit is an in depth 18 minute look at using foam as a mold. I bought a kit from LV a while back and have been using foam as a mold for chair components and the stuff works great.

High density foam can withstand 14 pounds per inch of pressure, no problem so it makes it ideal for this type of application.

I think this company has been inovative with their ideas and gives a fresh look at an area of woodworking that that needed a re-think.


Roarockit