How thin is too thin for a Hickory backing?

[barebo]

How thin is too thin for a Hickory backing on a quarter sawn Hard Maple core?

[willie]

hard to say, maybe a thin as you can work with? depends I guess on why you think you need a backing on the quartersawn hard maple?

[Hamish]

I've never seen anyone use less than 1/8".  Whatever is the minimum amount that will work, I don't know. What I do know is that the wood still needs to be straight grained, or you are wasting your time and materials.

Much of it comes down to what tools/machines you have access to. Most thickness planers won't go much under 1/8", due to safety and the strips internal integrity, before it gets chewed up.
Thinner pieces can be done safely if you have a thickness sander/drum sander.

You could feasibly laminate a backing, using 2-3 thin strips, say 1/16", and get a finished backing 1/8" - 3/16" thick.

[barebo]

I haven't posted here literally in years - life happens. I was talking to a fellow and mentioned that I had made a decent number of bows since '99. He said he'd love a longbow.
I had this 3/4 x 2 x 72" Maple blank and 3 nice straight grained Hickory backings. I decided to try an American longbow. 1 1/2" wide limb to 18" tapered to 7/16" tips so far. 70" NTN.
Backing glued on with Titebond 3.

I have it tillered nicely to 18" and it seems to be about 65# or so. I know Hickory is tension strong and don't want to overpower or chrysal / fret the Maple belly. Holding 1" of reflex. I sanded the Hickory that was just 1/8" down a 32nd and trapped the back but even scraping 25 or 30 strokes, she's stubborn to come down in weight. Looking for 45 -47#@28".

Love to get pics but have to figure out how to downsize them. I used a 3/4"x10" riser block of Honduran Rosewood with a 1/4x6" knife scale of Black Limba over that for the grip - not shaped yet, and have the Limba tip overlays on.

I could have just used the Maple without the backing but I remember Mark Baker made some Hickory backed Maple longbows that were pretty snappy so giving it a go.
After not making shavings for a long spell at 67 with a bum hand it sure feels good!

[Pat B]

You could probably go a 16th under 1/8" for the hickory backing with no problems. I've never had a hickory backing overpower a belly slat and I've made a bunch of hickory backed bows. If you find the maple belly is getting too thin but is still too stiff you can narrow the width a bit to help reduce weight.

[barebo]

Thanks Pat. I was going for more of a flatbow style with straight limbs then a taper to the tips but maybe should have gone straight taper from fades to tips. Not too late to reshape it but I'm going to thin the limbs a bit more and see if it wants to give up a bit of weight. Not going to push it - no need to hurry.

I'm going to try to figure out how to downsize pics to show you what I have to work with. Thanks again,

Mark

[barebo]

Hope this is the right size! The riser to fades is not right in this pic but is now. Now that the pics are figured out, I'll get a few better ones.

[Pat B]

Barebo, I meant to say a 1/32" under 1/8" and not 1/16".
 Look on page 2 at my "Starting a new ALB". It is hickory backed locust with a straight taper from the fades to the tips, basically a pyramid, ALB. I did a build along that might give you some ideas.

[barebo]

Believe it or not Pat, your bow was my inspiration to build this one! I did some research and most don't like Maple backed with Hickory. I've done half dozen Bamboo backed Hickory that were very nice bows. Can't afford Osage or Yew, but a nice Hop Hornbeam or Hickory stave have been my go to woods in the past.

Thanks for your input - Much appreciated. I'll be shaving away this afternoon.

[Marc St Louis]

I've used backings under 1/8"

[barebo]

Hi Marc,

That's what I was hoping to hear. I've always admired your work so having heard you've done so is good news. I thinned mine down as much as I dare and it has helped I believe to aid in dropping some poundage and coming around to a nice arc. I'm amazed at how much material has been removed but I'm very close now. I'll try to get a pic of it bent tomorrow.

[barebo]

Got it to low brace drawing about 23" and it is about mid 50#. String tracks dead center so no twist in the limbs. I have a rope and pulley on a 6x6" vertical beam in my utility room so getting a tiller shot is tricky. Maybe I can get my wife to snap a pic while I'm bending it.

[Dances with squirrels]

I too have used quartersawn hickory backings at no more than 1/16" thick. Usually on woods like cherry or walnut where I was concerned a thicker backing piece might be too much for the belly to resist. Some I ground in a drum sander, and some I thinned by hand after glue up. Worked good. Made good bows that held no less glued in reflex than those with thicker pieces.

[barebo]

Well,

I wished that I'd thinned it even more than I did. As mentioned above, perhaps I should have made a simple bow from the quarter sawn maple. I was at 45# final tiller @28" and looking good.
Shaped the grip and commenced to sanding with 320 and thought I set my drawknife down with it's razor edge too hard about 4" below the bottom limb fade but it didn't sand out. Tiny fret on the very surface.
I removed wood both sides and had to shave a bit from the upper limb as well. The fret was on the surface. Dropped to almost 42#. Strung it back up and let my nephew draw it so I could get a good look at the tiller at full draw, and the fret came back. I let some superglue soak in and am kind of bummed as it is light and has a nice bend. I'm going to shoot it when it stops snowing here in Central NY. I'll have my wife get a pic of it drawn.

[Pat B]

You can thin the backing now if you want. The nice thing about board backings is you can reduce the backing even when it's on the bow.