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Main Boards => The Bowyer's Bench => Topic started by: NRudder on May 03, 2011, 12:13:00 AM

Title: Form Questions
Post by: NRudder on May 03, 2011, 12:13:00 AM
If I'm making 1 3/4 '' limbs should i make my form / press 1 3/4 '' or 2'' ?

what can i use as a pressure strip
what can i use  a a formica strip
Title: Re: Form Questions
Post by: rogers on May 03, 2011, 12:30:00 AM
I would start with 2" that way you have room to work in case anything slides around and gives you room to sand.  I use galvanized metal strips for a pressure strips I'm sure you can find at Lowes or similar places.  I'm sure you could find formica at the same places.  I use thin plexiglass with a 1/8" rubber strip on top on my forms that dont bend to radical.  Hope it helps.
Title: Re: Form Questions
Post by: Rutland on May 03, 2011, 12:35:00 AM
You want your form to be as close to the limb size as possible.  The limbs will slide apart if the form is too wide when compressed, then in order to correct it once dried you will end up with a narrower limb bow.  Many bowyers use washers with a hole drilled to one side then attached to the form with wood screws so that when everything is glued up and placed in the form you swing you washers up to "brace" the laminations to keep them from sliding when compressed.  Then answer 1 3/4
Title: Re: Form Questions
Post by: Mike/Columbia Basin on May 03, 2011, 01:21:00 AM
I've got both 2 and 1-3/4 but I use metal straps
like Rutland uses the washers to keep the lams lined up straight. The 1-3/4 glass is cheaper so you might take that into consideration.
Title: Re: Form Questions
Post by: Bowjunkie on May 03, 2011, 12:22:00 PM
If you want the limbs 1 3/4" FINISHED, then you had best use 2" wide materials and forms for glue up. Even with side plates, things don't always go perfectly every time. Gives you valuable extra layout room you'll wish one day you had too.
Title: Re: Form Questions
Post by: Greg Szalewski on May 03, 2011, 01:12:00 PM
I do as Bowjunkie says. 2 inch material on 2 inch form. Wedges like to shift around along with everything else. Then everything should clean up when you sand it down to 1 and 3/4. 36 grit belt will take that down in no time.
Title: Re: Form Questions
Post by: Dick in Seattle on May 04, 2011, 12:15:00 AM
I went through the shifting layups syndrome and arrived at the conclusion that at least for me, exact width is best.  I cut my lam blanks slightly wide and when I have everything ground, I lay it all together and run it through the sander on edge until it measures exactly the same as the form.  I use large washers on the form sides, including up at the tips.   I've also gone to using full length lams unless I'm obsessed with the look of a particular piece of wood that isn''t that long... I try to avoid having to join lams.  I have a lot of wood on hand that's 36" to 40" and I'll use it up, but all the new wood I'm buying is 6' minimum.
Title: Re: Form Questions
Post by: NRudder on May 04, 2011, 01:28:00 AM
Thanks every one!!!