Pressure Bow form

[kurogane_84]

Hello all im thinking about making a pressure form, I wanted to steam a hickory stave that was roughed out and place it into the form and apply pressure to shape the wood into the shape of the form, using 2 laminated 2X6 boards, and a 2 inch hose for pressure ive seen ALOT of forms but have no experience building one, any and all advice on this would be welcomed

Im new to bowyering from a whold stave, ive made survival bows just good enough for a couple shots,  nothing more than that, im realy in need of help LOL

[iowabow]

Well you are at the right place to learn to build a bow. Keeping thing real simple on the first bow is a good idea. Sounds like a board bow is what you want. The form is called a caul and there are many different types. Maybe someone else can ring in here and make some suggestion as how to start.  They are going to need some information first before helping you. So what is your draw Length what # bow do you want. I would suggest you start with a basic style . There are many great bow makers here that can help you make your bow.

[kurogane_84]

Well you are at the right place to learn to build a bow. Keeping thing real simple on the first bow is a good idea. Sounds like a board bow is what you want. The form is called a caul and there are many different types. Maybe someone else can ring in here and make some suggestion as how to start.  They are going to need some information first before helping you. So what is your draw Length what # bow do you want. I would suggest you start with a basic style . There are many great bow makers here that can help you make your bow.

I agree there are many great craftsmen on here, ive seen alot and they are all beautiful i just hope i can be a 1/8th as good as they are

and my draw length is 28 inches and id be aiming for a #45 draw bow, and i never knew they were called caul, i have to google that now, thanks for the nights project

[bubby]

what iowabow said, i'm quessing your wanting to build a r/d style laminated bow, very tough for a first bow, let us know what your planning and we'll go from there, Bub

[kurogane_84]

what iowabow said, i'm quessing your wanting to build a r/d style laminated bow, very tough for a first bow, let us know what your planning and we'll go from there, Bub

its not goign to be my first bow, im just planning to make a form so that i can put some curves into staves, and also use the form for as you said making some r/d style laminates or composites

what im looking to do first off is to just get the form to bend wood that ive steamed, into either a r/d shape or add more deflex to staves, i have an idea for a out door steamer, i have a old 45 gallon drum, i was goint to cut ithalf way up and weld on a base of steel and build up a steamer box out of it lol

[gstoneberg]

Having used an air hose pressure form for laminated bow glue-ups and a caul for heat bending, I have to say they are almost 2 different animals.  There's no way you'll be able to take a heated/steamed bow blank, lay it on the pressure form base, add the hose, push the top of the pressure form in place, tighten the clamp bolts and inflate the hose before the wood has lost so much heat that it won't bend.  That will only work with thin laminations in a glue up where you have some time before the glue sets to get everything into position.  Even then you feel like you need a couple extra hands before you're done to keep the bow in alignment.

It might be possible to build a dual use pressure form base with holes for clamps so you could clamp a bow in it as it's heated and then use clamps to pull it against the form.  However, I think you'll find that things will work better with 2 purpose built forms, one for laminating and one for heat bending.

George

[kurogane_84]

Having used an air hose pressure form for laminated bow glue-ups and a caul for heat bending, I have to say they are almost 2 different animals.  There's no way you'll be able to take a heated/steamed bow blank, lay it on the pressure form base, add the hose, push the top of the pressure form in place, tighten the clamp bolts and inflate the hose before the wood has lost so much heat that it won't bend.  That will only work with thin laminations in a glue up where you have some time before the glue sets to get everything into position.  Even then you feel like you need a couple extra hands before you're done to keep the bow in alignment.

It might be possible to build a dual use pressure form base with holes for clamps so you could clamp a bow in it as it's heated and then use clamps to pull it against the form.  However, I think you'll find that things will work better with 2 purpose built forms, one for laminating and one for heat bending.

George

That was what i was fearing,  oh well ill be building 2 forms then , one for clamps and one for laminations, i was thinking of laminating 2 boards, to make the forms, using 2 X 12s drawing the shape i like onto the board cutting it out with a band saw and smothing with rasps and planes, then applying a smooth coat of varnish to it and like ive noted on a few posts they used some copper on top of the form, incase i decide to use a heat gun instead of steam.

Please tell me if im over thinking or planning this out way too much, i tend to do that LOL

[Pat B]

Here are a few forms I use for bending, straightening, adding reflex and recurves. They are very simple to make and are made from scrap wood. I use a heat gun for all of my heat work on bows.

[gstoneberg]

Nice Pat.   I also use just dry heat.

I emailed you a link to a form making page for laminated bows.  Most people put something like linoleum on their glue-up forms so it resists the glue sticking to it.  I don't put anything on forms for heat bending self bow limbs.  I'm not sure I'd use copper as it will conduct the heat around to the limb back where you don't want it.  It is very easy to scorch the limb right where it meets the form.

George

[Pat B]

Kuro, check out my build along on a 60" static recurve I built for last years Bow Trade. It is in the "Archives(reads only) thread.

[kurogane_84]

Kuro, check out my build along on a 60" static recurve I built for last years Bow Trade. It is in the "Archives(reads only) thread.

Ive reviewed your post Pat, looks great, i think ill copy your form design lol, could you give me some dimensions on the forms?? what size wood did you use for the deflex??

[Pat B]

It is all dimentional lumber(2x4, 2x6) or scraps. For the recurve form I used a 5gal bucket to get my curve. For the reflex form I went from 3 1/4" to 0 on the last 6" of the 2x4.

[kurogane_84]

ok perfect, ill probally use the design

[bubby]

for a wood lam bow you dont need a real fancy form, you can cut your profile and wrap with innertube strips heat is not really needed, Bub