Dimensions of LVL form

[Bruce Martin]

New to fiberglass bows but going to build a few to see how it goes. Initially I am building a mild reflex deflex longbow from Binghams plan. It seems LVL is the preferred material for a sturdy and straight form and I am using a pressure hose system. I bought a 1.75 inch wide x  9.5 inch deep piece that is 8 ft long from Home Depot. Looks good but I am worrying 9.5 inches is not enough to cut into a top and bottom to be beefy enough for a long one piece form. I suppose the most material would be needed for the top to accommodate the riser. Do you folks recon I had better get another board to make sure the form is strong enough or make a rubber band form out of this one and plan better for the next with the air hose? I thought I was getting a 12 inch deep piece but the guy must of heard me wrong. Have to order these, they do not stock them.

[bornofmud]

You could put some iron or steel strips on the top and bottom of the form if you're worried about it.  Haven't used LVL personally, hear it's good stuff.

[Robertfishes]

Yes if you want to use the fire hose you will need another piece for the top. I would think you would have needed a 16" piece for your mild R/D form.

[bjansen]

double post

[BigJim]

I use 12" wide pieces for my R D bows unless I get a deal on wider ones.

I would ensure that you have more strength on the form side as this will control your shape. Over time, you could possible get some flexing or drifting of the top, but since we typically use more than enough air pressure to do the job, at least the bow will take on the proper shape.

Forms that are way too large are way too heavy and over time will wear on you.
BigJIm

[Bruce Martin]

Thanks so much for those suggestions. I will get another piece and make it right.

[Mad Max]

use plywood for the top and your LVL for the bottom

how much $ was the LVL

[Bruce Martin]

The board was from Home Depot but made by Georgia Pacific and was $35

[Pat B.]

         

To Big Jim for all his contributions here !!

[Bruce Martin]

Right on! Eventually I want to build a r/d bow with reinforced riser that I can cut in half and make the fiberglassed takedown by Jim's method. His video of the process is excellent... And with someone of his experience in building great bows I certainly am glad for the advice on form building.