Glass Laminating Question

[DavidWood]

Has anyone successfully made a glass laminated bow without a heat box?  If so, how well did they hold up?  Were there any problems?  Mostly importantly, what epoxies and/or glues were used?

[Joel Watts]

I did. I used smooth on. All I do is put it in a small bathroom with a heater. It got to about 100 degrees in there for about 2 hrs. and I let it stay in the form for 24 hours. Some people say that without a hot box, it will delaminate at a lower temperature but I haven't found that to be the case.

[Brett Leinmiller]

I'm fortunate enough to know a great local bowyer, John Holzrichter. He's been building bows for a long time and his hotbox is just a plywood box with lights inside for heat and I think he has reflective material in it. Its not air tight and it works great. He uses Smooth On.

I'm not a bowyer, yet:), but I know that a bow needs to be tested over a period of years to determine whether building without a hotbox Is a good idea. Given the low expense and ease to make one, I'll be using one when I get my shop started.

[Bowjunkie]

I have. I cured them at room temperature, 70 degrees. No issues. I use Smooth On.

[sque1ch]

I've had good results with wests flexi epoxy it is available in runny and thick which is a good gap filler. Only downside is a 16 hour cure time....

[sque1ch]

I've had good results with wests flexi epoxy it is available in runny and thick which is a good gap filler. Only downside is a 16 hour cure time....

[sque1ch]

I've had good results with wests flexi epoxy it is available in runny and thick which is a good gap filler. Only downside is a 16 hour cure time....

[BenM]

Lots of guys do a room temp(70*) 24 cure with Smooth On EA-40.  I wouldn't be afraid to try it that way.  I don't have the patience for it though.

[KenH]

I use open forms and no heat box all the time.  

It helps a bit being in Florida, but as long as the ambient temp where the bow is curing stays above 70-75F, epoxy will cure just fine in 24 hours.  I use EA-40 Smooth-on epoxy.

Heat boxes are great if you're a commercial bowyer turning out bow quickly, or have ADHD and can't wait over night for a bow to cure.   :rolleyes:    

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[hightop_hunter]

Im so glad you guys are talking about this. I have recently moved to another provence and don't have access to my dads shop. The bow bug bite me (again) but now i live in a basement sweet with no power tools. this encourages me to trying my hand at a glass bow. I figure I can do almost every step of the build with hand tools. I was worried about the box to build it i would need alot of extra space and tools but if you guys say it can be done without. I think i could manage. I always wondered if you had to bake a bow to cure it.

[KenH]

Hightop - you can certainly do everything except cutting a square/flat profile form with hand or powered hand tools.  To get that jig right you need a bandsaw to cut the curves square and flat.  Don't need to *own* a bandsaw mind you... just need to know someone who does .  

In fact my bendy-handle flatbow jig is just a 6 ft length of straight/flat pressure-treated 2x2 that I found at Home Despot for under $5.  Once I lay up a flatbow and spiral wrap the assembly, I can stand it in the corner while it cures.

My "workbench" is a 4x4 ft wooden box on a pallet.

[GentlemanArcher]

Hi...I've tried it too.  Works fine.  I do like the security of using heat though.  My "oven" is a square tube made form 1" foam insulation.  You can get it in a 4'x8' sheet.  Cut it in four long, 1 foot wide strips and tape then them together to form a long tube.  In goes the bow and put a 500W halogen work lamp on either side...180 degrees no problem.  With one lamp and the other end blocked, you still get ~150 degrees.

[hightop_hunter]

Hey Ken. a band saw has been on my Santa list for the last 10 years. I know im young but I like the big toys HAHAHA but i have made some connections in the film industry out here that would let me use the band saw in their shop. so now that i have that step covered. The only step that also worries me is once the bow is out of the jig the step after that is trueing up one side so that the centre line can be drawn on the back of the bow. from what i see most builders use a belt sander to flatten one side. Is there a way I could do that with out a belt sander. Thanks Again for your help guys

[KenH]

I draw the centerline on the masking tape cover of my fiberglass,before I every glue things up.  After the bow is off the form, I measure out from there in both directions and draw edge lines. You can make a simple "flat sander" by going to Home Depot or Lowe's and buying a marble window sill 4 ft long x about 6" wide, for about $10 or $15.  Then buy a long belt sender belt, say 80 grit, cut it and open it up into a long flat strip.  Then glue it to the marble slab which is dead flat.  I have a sander like that which I've used for making musical instrument sides and such as well.