Author Topic: Help please - can I squeeze two bows out of this ipe?  (Read 1462 times)

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Offline Freeflynick

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Help please - can I squeeze two bows out of this ipe?
« on: June 07, 2020, 01:51:01 pm »
Hello!
So I recently finished my 5th bow - a hickory backed ipe pyramid bow, and am very happy with it (see pic).
I have a leftover piece of ipe which is 1-7/16" wide x 3/4" thick x 72" tall. Do you think I could rip it in half (I think after the cut each piece would be approx. 0.3575" thick) and add a 1/8" hickory backing to make two bows, or would they be too thin?
Also, would this caused a problem at the fades or would well glued on pieces work in place of the ticker base material that would usually be there if a thicker board is used?
Thanks guys!!
Nick

Offline DC

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Re: Help please - can I squeeze two bows out of this ipe?
« Reply #1 on: June 07, 2020, 02:02:28 pm »
How thick is the Ipe at the fades on the bow in the pic?

Offline Freeflynick

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Re: Help please - can I squeeze two bows out of this ipe?
« Reply #2 on: June 07, 2020, 02:53:54 pm »
How thick is the Ipe at the fades on the bow in the pic?
Not sure where exactly you mean by "at the fades". The pic here shows the thickness as 5/16", tapering up to full 3/4" thickness in the handle, and a little further up the limb is goes to minimum thickness of around 1/4".
FYI - this one drew to 35# @28" and 40# at my draw of 31".
Does this help?

Offline Hamish

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Re: Help please - can I squeeze two bows out of this ipe?
« Reply #3 on: June 07, 2020, 04:34:33 pm »
You could do it, but you would have issues that need to be dealt with a different strategy to your previous bow.

You can put a 1/8" core lamination to make up for less depth in the ipe belly slat. It doesn't have to be more ipe, it could be maple, or some kind of coloured wood like purpleheart etc.

With a shallow bely slat, you can get issues at the dips/fades with the glueline opening up on the riser. You either need a really good glue, or you need to put a power lamination under the backing at the riser, fadeouts that will raise the glueline well above the belly, where the limb meets the riser.

Offline DC

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Re: Help please - can I squeeze two bows out of this ipe?
« Reply #4 on: June 07, 2020, 05:23:33 pm »
 

The numbers don't work out the normal way. If you cut the Ipe you would get two pieces .3575 thick. The 5/16" that you measured is .3125 . That gives you .040" leeway. Can you cut the Ipe in half with that much accuracy. That 5/16" is after tillering. You need a little leaway and you don't have enough. You could try it the way I'm doing in the "Fades" thread but apparently Ipe doesn't bend. I'd make one "fer shur" bow rather than try for two.

Or you could do it Hamish's way. Even that way I think you'd still run into the "Ipe won't bend" thing.

Offline Freeflynick

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Re: Help please - can I squeeze two bows out of this ipe?
« Reply #5 on: June 07, 2020, 08:58:18 pm »
You can put a 1/8" core lamination to make up for less depth in the ipe belly slat. It doesn't have to be more ipe, it could be maple, or some kind of coloured wood like purpleheart etc.

With a shallow bely slat, you can get issues at the dips/fades with the glueline opening up on the riser. You either need a really good glue, or you need to put a power lamination under the backing at the riser, fadeouts that will raise the glueline well above the belly, where the limb meets the riser.
Hamish - can you simplify / explain in a bit more detail, or even better, provide a photo or sketch? A core lamination - are you saying a third layer that would run the entire length of the bow, or just over the handle section? And I don't know much about power lams yet.....how would I determine the required length/shape/thickness required?
This is all great food for thought....being a newbie, there is so much I don't know, so these questions will be coming thick and fast, so please bear with me!

But, I am thinking I may be better off using the whole piece instead of trying to half it. I'm thinking of doing my first R/D next...but that brings up a whole new set of questions!

Cheers,

Nick

Offline Tommy D

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Re: Help please - can I squeeze two bows out of this ipe?
« Reply #6 on: June 08, 2020, 10:49:03 am »
So you would need to do two things if you split the Ipe in half. As DC has pointed out you won’t have much margin for error. Ipe won’t bend to do fades like he is doing. What Hamish has suggested a tri-lam bow. If you google it lots of examples of them will come up on here. Many people like maple I believe with bamboo and Ipe. Most suggest you taper your core (middle lam) from the handle to the tips before you glue up. This is so that when you tiller the Ipe belly you don’t run out of Ipe to tiller or end up with very thin Ipe at the tips - if that makes sense?

The next issue is the issue of glued on handles popping off. They like to do this if the handle is glue to a belly lam that flexes too close to where the handle “fades” or the ends of the handle join the belly of the bow. If you start with a thick belly lam, lay out your handle and tiller your bow, by the time your limbs start flexing you have left behind enough handle wood that the handle portion isn’t flexing. BUT if you use a thin belly lam and glue a handle on it because you don’t have any spare wood to scrape away your bow would flex too close to the handle and pop it off. This is why a “power lam” has been suggested. It is a shortish piece that fits between the bamboo backing and the belly wood. Say your handle plus fades is 8 inches, you might make say a 14 inch power lam that you glue in between the belly and the bamboo - it’s purpose is to stop handles popping off. They are typically like a 1/4 inch or so in the Center tapering to nothing at the ends either side.

You may be able to make your maple core such as it serves this function by making it thick enough at the handle section.

If you go on you tube and google Clay Hayes Bamboo backed R/D there is a very useful 28 minute video of them gluing up a bow with a power lam. Lots of good info there.

You can also google poorfolk bows and R/D and he explains the handle popping off part.

Ipe is hard to bend. So if you are thinking of doing a R/D you may do well with a trilam - there are lots of guys on this site who have made excellent bows like this.

If you are confident doing laminations, grinding some tapers and you can find a decent core wood then you can probably get two bows out of that Ipe. Otherwise do as DC says ... “A bird in the hand and all that”...
« Last Edit: June 08, 2020, 10:54:47 am by Tommy D »

Offline Freeflynick

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Re: Help please - can I squeeze two bows out of this ipe?
« Reply #7 on: June 08, 2020, 11:35:50 am »
THANK YOU Tommy!! This is a great reply for my level of knowledge. I appreciate the other responses, but unfortunately I am at that level where I have heard some of these terms but do not yet fully understand them, so taking the time to explain what they are and how they could be used in my situation means a lot to me.

I will definitely check out Clay's video - I am about halfway through reading his Bowyers Handbook and have studied a lot of his videos, but don't think I have been through this one yet.

So it is definitely sounding like I should just aim for one bow out of this piece of ipe. I will try and source some more, but this was the only board out of about 30 I looked at that had suitably straight grain. Hopefully I will get lucky again next time!

Thanks again for all the responses.

Nick