Largest Lam Thickness

[gfugal]

What's the thickest you've gon on a lam that's going into a bow form with a glued on handle? I have two wood laminations (excluding power lams, and wedge tips) that I'm planning on using as the core. One is going to be 4 mm (0.16") on the belly, and the other 6 mm (0.24") tapering down to 2.5 mm (0.098") that's going on the back. I calculated its taper rate at about 0.0041" for a 70" bow. My concern is whether it can make the bend onto the fades without breaking, and I'm debating steaming in those bends prior to glue up to prevent the risk of breaking them.

[gfugal]

I should also mention that my form has quite a bit of reflex built into it straight out of the handle (4-5") so that's why I have larger taper rate, plus I'm going to use tip wedges, so hopefully I won't get too much whip tiller.

[ty_in_ND]

What are your riser's dimensions?

I did a dry run with ASL-style longbow where my riser section is 15" long and a 4.5" handle length and 1.5" deep. The fades are fairly mildly curved.  I had a .130 lam running up those fades and while it will work, I probably wouldn't go any thicker than that for that particular riser. I'm still debating about whether or not I want to have the lam run under the riser or just have the glass under it and keep all the lams together.

[gfugal]

My Riser is a little over 8" long (hence why I'm going to do a 12" power lam). I'm not entirely sure on the dimensions though, but I can measure and check back later. It isn't very thick (like maybe 1.25") with maybe 2.25-2.5 inch fades. I like smaller handles. I might do the steam method regardless. I don't want to go much thinner because I think I need my stack that thick.

[Bvas]

Personally, I wouldn’t steam bend. You could also end up causing the lams to cup which could create bigger issues.
I would get the riser cut and try fitting the lams. See how much pressure it is gonna take.
You could also sand the lams parallel from the fades back to reduce thickness slightly.

[BMorv]

Sorry just saw this with all of the new website stuff. What does your form look like?  A pic would help. 
I use .24 belly lams a good bit and they can take a good amount of bend. 

[monterey]

I don't think you need to prebend if you are using a hose form but if it's a rubber band form, I'd move all the lams under the riser and go with glass only up the ramps or a thin lam between the glass and riser.

[gfugal]

Well, I've already glued it up. I tried doing a dry run and it would not go down far enough before I heard creaking. So I clamped it with a bar clamp as far as it was safe to go, heated it up with dry heat and clamped it down the rest of the way and cooled it. I also had to do the same for the recurve since they are sharper. I got minimal to no cupping, probably because of how thick the lam was 4mm ≈ 0.16". I glued it up, and it held together but wasn't the prettiest thing with large glue lines (no gaps mind you). I think it was a combination of too thick of a lam, not a gradual enough fade on my riser, and the fact that I made my own lams with a caliper, straight edge, and rasp. So the fact it glued up at all is a miracle in of its self 

I'm not too disappointed since this is my first go, but not only that but because it was a rough "proof of concept". I'll have to share the bow with you all as soon as I get it finished.

[gfugal]

Here's the bow during glue up on the form



Here it is out of the form



And here is the riser area, but it has glue and gunk all over it. The lams were also of different widths. So that's not a gap where that dark line is, but a shadow. There weren't any gaps from the glue up. Sorry, it's hard to see, not to mention the quality of the picture is bad. Sorry about that.

[BMorv]

So it’s all wood no fg.  Yeah I would say that’s a little thick to bend to the radius of that riser.  Maybe the glass guys have more specifics on max thickness