Trad Gang

Main Boards => The Bowyer's Bench => Topic started by: mikkekeswick on October 16, 2014, 09:12:00 AM

Title: 1st glass bow.....1st mistake!
Post by: mikkekeswick on October 16, 2014, 09:12:00 AM
Hi, i've just glued up my first glass bow and unfortunately i've made a soggy wet noodle bow! It's only 17 lbs @ 28.....
So instead of never shooting it I was wondering if it's feasible to glue another layer of glass onto the back or belly? I've got glass in 0.30 , 0.40 and 0.50 thicknesses. Also I have no idea yet as to much this would raise the weight?
I'm also happy to just learn from it and make another if this is the best option. In fact i'm not totally happy with the shape of the form anyway.
The positives are that the tiller was perfect and everything went to plan.
Title: Re: 1st glass bow.....1st mistake!
Post by: JamesV on October 16, 2014, 12:06:00 PM
Mike..............

I would tweak the form and build another bow. Could shorten that bow and give it to someone.

James
Title: Re: 1st glass bow.....1st mistake!
Post by: mikkekeswick on October 16, 2014, 04:59:00 PM
Yep that's what i'm thinking. Onto the next one!
Title: Re: 1st glass bow.....1st mistake!
Post by: KenH on October 16, 2014, 05:45:00 PM
Depending on how much you tweak that form, you could use the Lam Stack Calculator to find the total stack thickness for a second bow based on the results of the first bow.  

I've taken to making a prototype bow from each new form as absolutely cheaply as possible:  thin cheap glass, and a thin single lamination core about 1/8" thick cut with a tablesaw from cheap pine.  Once I have that bow's draw weight, I can plug that and the prototype stack thickness into the Stack Calculator, along with the desired new bow draw weight, and up pops the total stack thickness for the first "good" bow.  I then divvy that stack thickness up as I see fit between glass and various thin lams of wood.
Title: Re: 1st glass bow.....1st mistake!
Post by: Pheonixarcher on October 17, 2014, 05:26:00 PM
Sounds like a useful tool. Where can we get this stack calculator?
Title: Re: 1st glass bow.....1st mistake!
Post by: mikkekeswick on October 18, 2014, 02:34:00 AM
Yes indeed! Where oh where is this 'stack calculator' available?
Title: Re: 1st glass bow.....1st mistake!
Post by: Andy Cooper on October 19, 2014, 11:45:00 PM
http://www.filedropper.com/lamstackcalculator-bjansen