Roy my forms are solid 1.5 x 72" with varying degrees of backset.  I do want to build a form with posts like you have as well. Your concave idea sounds good, worth a try....Hop to it!

Then it may be your clamps exert too much pressure in one spot compared to the fire hose?

Ya have pitcher of your form?

Quote from: Stagmitis on January 23, 2021, 09:38:54 AM
With a double glue up I can first excerise the limbs removing all stress, easily achieve string alignment and tiller and fine tune limb bend then add glass when everything is perfect.

Do you draw it to the full draw length while doing this? Do you ever see it take some set before you put the belly glass on? How does adding the belly glass change the tiller?


Mark

Yes mark always takes set...I start slow excersizin often and eventually reach full draw.

Roy it could be clamp pressure even though you have a pretty good feel when tightening down the clamps. Ill get a pitcher

Cool, Miller Light works.....

I better get a keg if its that light stuff 

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Heres an old one that isnt in storage  On top of lams I use a 1/4" x 1.5" hard rubber strip, metal pressure strip and wood blocks running the span between clamps. Strip of glass against form that lams sit on.

LOL on keg.

Cool on form.

Thats old school style building, Charles!
Thats how they did it when first experimenting with glass and other backings. I have never tried that method.

Quote from: Stagmitis on January 23, 2021, 04:39:59 PM
Yes mark always takes set...I start slow excersizin often and eventually reach full draw.

Stag, are you able to tiller to a given weight and project what the finished weight will be after adding the belly glass?   If you are willing to share a few numbers, I would like to try to see if it agrees with some calculations I have been trying out.

Willie finished weight is not an exact science because it depends on how much material comes off to tiller and align the string. Usually if dimensions arent changed much then the outcome is very close to a single glueup. There is a formula if the bow is weighed before the belly glass is added I just dont remember what it is.

I dont concern myself with weight anymore. If high, I used to trap,sand belly glass,maybe change width profile...It alters my design and reduces performance. I would rather build another than change those things to hit weight.

On a different note I was surprised the first time I did a double glueup. Without the belly glass the limb bend showed a hinge coming off the fades and the tips a tad whippy. I couldnt see this when glassed altogether. It helped me fine tune my tapers.

Quote from: Stagmitis on January 26, 2021, 08:49:28 AM

I dont concern myself with weight anymore. If high, I used to trap,sand belly glass,maybe change width profile...It alters my design and reduces performance. I would rather build another than change those things to hit weight.

On a different note I was surprised the first time I did a double glueup. Without the belly glass the limb bend showed a hinge coming off the fades and the tips a tad whippy. I couldnt see this when glassed altogether. It helped me fine tune my tapers.

thanks for the details and observations.