Bow head repair approach ?

[Guido]

This stick has a break behind the head as indicated on the picture. I runs forward with the grain a couple of cm.

Under hair tension the break flexes open ever so slightly.

I'm thinking to glue with a strong hide glue in anticipation of further trouble down the road. My main concern would be to get sufficient glue into the crack.

I'm wondering if a thin CA glue would be more successful initially (but more trouble down the road if it fails).

Any opinions/ ideas?

[CVA]

I'm afraid this type of damage is commonly referred to as a "lift." When a bow sustains a significant lift or a crack behind the head, its value declines sharply, often amounting to the worth of the frog and button. The typical repair involves gluing the split and reinforcing it with a thread wrap. While this restoration can sometimes hold for many years, it may also fail prematurely, unfortunately.

Edited March 17 by CVA

[Chamberlain]

2 hours ago, Guido said:

This stick has a break behind the head as indicated on the picture. I runs forward with the grain a couple of cm.

Under hair tension the break flexes open ever so slightly.

I'm thinking to glue with a strong hide glue in anticipation of further trouble down the road. My main concern would be to get sufficient glue into the crack.

I'm wondering if a thin CA glue would be more successful initially (but more trouble down the road if it fails).

Any opinions/ ideas?

If you are ok having it look like a repair you could do the glue and reinforce it with a small thread winding collar over a portion of the break area to reinforce it and then seal with glue and smooth. 
I’m sure others might have different ideas.  Especially if you’re looking to conceal it. 

[Guido]

35 minutes ago, Chamberlain said:

If you are ok having it look like a repair you could do the glue and reinforce it with a small thread winding collar over a portion of the break area to reinforce it and then seal with glue and smooth. 
I’m sure others might have different ideas.  Especially if you’re looking to conceal it. 

Good idea, structurally. I’ve seen it a few times. But whenever I see a bow with a thread over a break/ lift I always assume the worst as you can’t see the extend of the damage anymore.

I was considering possibly a pin; but maybe only if glue only fails.

”Concealing” is not an objective. I’d be quite happy for the break to remain visible for what it is, especially if the bow is to change hands in the future.

[fiddlecollector]

Your lucky that the grain direction is relatively straight and not angled down into the head. Another option is to mill away the area and glue on new wood but its alot more complex. How deep into the stick does the crack go on the side we cant see in the photo.

[Guido]

16 minutes ago, fiddlecollector said:

Your lucky that the grain direction is relatively straight and not angled down into the head. Another option is to mill away the area and glue on new wood but its alot more complex. How deep into the stick does the crack go on the side we cant see in the photo.

It's harder to see bow in hand than in the photo :-)

The crack running with the grain extends about the distance between the two arrows.

[Guido]

Pondering this a bit I'm currently leaning to a thin CA glue, rather than a strong (and somewhat thick) hide glue.

And I think I'll want to leave it at glue-only for the time being.

Any major objections before I get the glue out of the fridge?

[martin swan]

It wont hold without some kind of whipping.

you could use very fine monofilament - 1kg breaking strain - which becomes relatively invisible if you varnish it.

[Chamberlain]

8 hours ago, Guido said:

Good idea, structurally. I’ve seen it a few times. But whenever I see a bow with a thread over a break/ lift I always assume the worst as you can’t see the extend of the damage anymore.

I was considering possibly a pin; but maybe only if glue only fails.

”Concealing” is not an objective. I’d be quite happy for the break to remain visible for what it is, especially if the bow is to change hands in the future.

The CA glue might hold better than hide at the highest tension area of the bow. The wind collar could be size of rehair wrap so smaller soaked with CA glue. 
Glad concealing isn’t objective. Do they still mark mortises or tip plate with red to notify others of concealed repairs? 

[M Alpert]

2 hours ago, martin swan said:

It wont hold without some kind of whipping.

you could use very fine monofilament - 1kg breaking strain - which becomes relatively invisible if you varnish it.

Interesting, like fishing line or what? Can you tell a brand?

 

[M Alpert]

9 hours ago, Chamberlain said:

If you are ok having it look like a repair you could do the glue and reinforce it with a small thread winding collar over a portion of the break area to reinforce it and then seal with glue and smooth. 
I’m sure others might have different ideas.  Especially if you’re looking to conceal it. 

I prefer that this sort of repair remains clearly visible. As previously mentioned, the value should dive with such a lift crack, I suppose it is not standardised exactly - I personally don't think it should devalue like a splined head, but some think so. Opinions?

As for glue, I like Loctite Precision for this type of thing. Or fresh, relatively thin hide glue. I believe it is a myth that jelly thick glue is stronger.

I use a strong polyester or silk thread that matches the stick color and cover it with CA.

[Chamberlain]

3 hours ago, martin swan said:

It wont hold without some kind of whipping.

you could use very fine monofilament - 1kg breaking strain - which becomes relatively invisible if you varnish it.

Thank you.  I would like to try this. Could you share if it’s with CA to hold with the knots and if you seal over the varnish on the monofilament?

[Chamberlain]

33 minutes ago, M Alpert said:

I prefer that this sort of repair remains clearly visible. As previously mentioned, the value should dive with such a lift crack, I suppose it is not standardised exactly - I personally don't think it should devalue like a splined head, but some think so. Opinions?

As for glue, I like Loctite Precision for this type of thing. Or fresh, relatively thin hide glue. I believe it is a myth that jelly thick glue is stronger.

I use a strong polyester or silk thread that matches the stick color and cover it with CA.

That looks nice. It can be an elegant repair and preserve the playability of the bow. Much better than the inch long soldered wire casts I’ve seen! 

[HoGo]

18 minutes ago, Chamberlain said:

Thank you.  I would like to try this. Could you share if it’s with CA to hold with the knots and if you seal over the varnish on the monofilament?

Monofilament is nearly impossible to glue and hard to knot without slipping, you need to use fisher's knots and/or pull the ends under the wrap and lock them somehow. I'd probably go for silk or embroidery thread, you can find one that matches the color perfectly or thin silk with varnish can be nearly transparent (test on samples).

Thin quality CA over hide glue for me on these exotic hardwoods. You can wash away CA with acetone if needded (though that may destroy many finishes)

[Chamberlain]

17 minutes ago, HoGo said:

Monofilament is nearly impossible to glue and hard to knot without slipping, you need to use fisher's knots and/or pull the ends under the wrap and lock them somehow. I'd probably go for silk or embroidery thread, you can find one that matches the color perfectly or thin silk with varnish can be nearly transparent (test on samples).

Thin quality CA over hide glue for me on these exotic hardwoods. You can wash away CA with acetone if needded (though that may destroy many finishes)

 

[Chamberlain]

Thank you. I fish often so I’m pretty confident I could get a knot to hold on it. I was thinking the imitation whale bone wrapping method could work also if able to be secured additionally. 
The CA over hide glue is interesting.  

[HoGo]

I meant I prefer CA over Hide, not two layers

Fishing monofilaments are very stretchy, you want something more stiff. Even simple good quality sewing thread in this application wilI be plenty strong. I'verepaired arrows by simply cutting off at angle and adding new part of stick. 1" long joint with just thin thread wrap holds so well that arrows that broke again broke at different spot.

I used to fish too :-)

 

[Chamberlain]

9 minutes ago, HoGo said:

I meant I prefer CA over Hide, not two layers

Fishing monofilaments are very stretchy, you want something more stiff. Even simple good quality sewing thread in this application wilI be plenty strong. I'verepaired arrows by simply cutting off at angle and adding new part of stick. 1" long joint with just thin thread wrap holds so well that arrows that broke again broke at different spot.

I used to fish too :-)

 

And here I thought you were creating your very own artier two part epoxy 

[fiddlecollector]

Here the result of 10 minutes work using 0.05mm (0.001968504")   monofilament  .stuck easily with ultra thin CA by Starbond.  I havent fussed about with it much apart from sealing with the CA and when dry a light sand with micromesh and a rub with acetone to bring back the transparency. One photo with flash one without. I could have made a better job of it using a magnifier but i was having trouble seeing the stuff.

 

Looks alot more decreet than this Bazin bow i sold someone 20 years ago which got broke  in shipping and the buyer had it repaired by the Raffin shop.

 

[Chamberlain]

6 minutes ago, fiddlecollector said:

Here the result of 10 minutes work using 0.05mm (0.001968504")   monofilament  .stuck easily with ultra thin CA by Starbond.  I havent fussed about with it much apart from sealing with the CA and when dry a light sand with micromesh and a rub with acetone to bring back the transparency. One photo with flash one without. I could have made a better job of it using a magnifier but i was having trouble seeing the stuff.

Thank you! It looks nice. Did you do anything other than CA to start and stop the ends? 

[fiddlecollector]

No i wet the stick a little and just over lapped the first winding. when it was held i just wound to the end ,then soaked it in the CA ,it dried fast and i just cut the end off flush with a sharp knife.No Knots.

[Chamberlain]

5 minutes ago, fiddlecollector said:

No i wet the stick a little and just over lapped the first winding. when it was held i just wound to the end ,then soaked it in the CA ,it dried fast and i just cut the end off flush with a sharp knife.No Knots.

Thank you! I might try the whale wrap end winding over loop and pull and tuck the tail method with it too. 

[Brad Dorsey]

9 hours ago, Chamberlain said:

…Do they still mark mortises or tip plate with red to notify others of concealed repairs? 

Who does/did that?  I have never heard of it.  If the red were removable, it would accomplish nothing.

[Mike_Danielson]

I would use CA glue.  To make it invisible, use a half round file to remove wood on the upper side (tensile side) and inlay a fingernail piece of similar wood using G-2 epoxy.  The inlay can be very small, but you must cover the trans-grain fracture of the crack to prevent the crack from re-initiating.  File, scrap, and sand back, fill the wood with a sealer like shellac and then get the water color paintbox out to match colors.  French polish.  In time, this repair will become invisible.