Riser pulling apart...help

[elk ninja]

I am working on a couple (fiberglass lam) bows at the moment, but one riser in particular has me stumped.  It's a first on a few fronts.  First bocot riser, first time working with ebony, first riser that has two woods (I generally like simpler styled risers), but most important, the first time my riser has pulled apartlike this:
 
You might be able to see the ebony has pulled away from the phenolic and bocote.  
Here is another picture to get the scale:
 
and it is pulling away on the other side as well.  
The ebony comes dipped in wax.
I THINK I should be able to shoot some CA glue into the cracks and clamp it down.  I'd try smooth on if it was thinner....
I'd really like to salvage this riser due to the cost of the ebony but if it's junk, its not worth wasting a set of limbs either (one piece RD longbow by the way).
Also, this might enter into the equation....
the limb transition comes up about an inch into the ebony, so that joint is actually covered and would most likely not be a cause for a blowout.

Anybody have any ideas?

Mike

[fatman]

I don't know about bow building, but I do know glue (it's my business)...would strongly recommend against using CA.  CA's have excellent tensile strength, but relatively poor peel strength. I'd recommend thinning your epoxy of choice, maybe with acetone...or try working some Smoothon in there....

[PV]

The phenolic has pulled away from both woods. I would try cutting the phenolic and salvage the wood.If you used a jig for your radius maybe set the riser on the jig to cut it out? Was the phenolic sanded both sides? Beautifull riser BTW.

[freeman]

If there was still a bit of the surface wax you mentioned, maybe it could have been spread by your bandsaw blade through the cut???

[wingnut]

The ebony was wet and is now drying.  One of the reasons I hate working with ebony.

Usually end up rebuilding the bow when that happens.  You can try to fill it but you never know how much it will shrink.

Mike

[GameGetter]

I agree with maybe the moisture content was too high. Maybe cut it apart at the phenolic as metioned then get the moisture content right and reglue. JMO!

[Aram]

I would rebuild it also. I don't have much experience with CA and woul dalways worry after. What kind of glue did you use? Looks like it could be a glue problem since it came off both sides of the phenolic. Before cutting you can put a little wedge pressure in the existing crack and see if they will completly pull away. You would know right away, don't force it too much. If the bond is good you don't want to split the ebony. Good luck and post the results.
Aram

[kennym]

Does the grain in your ebony run opposite the bocote?

[Blkbird]

Both woods are turning loose of the phenolic. Makes me think phenolic was not perped properly.

[elk ninja]

I used 2.5 ton epoxy, roughed up both the wood and the phenolic real well, cleaned all pieces with acetone.... the ebony grain is running funny, but the piece came covered in wax and it was what I had to work with.
Lesson #1: Unwax the wood and let it sit for a good long time.
Lesson #2:....TBD
I think I am going to let it sit for a bit.  I might just run out to woodcrafters and get another chunk of something.  I do have enough ebony left over to give it another go.  I'd try to bandsaw it out, but that would be tricky because, un-noticed by me when I cut the crescents out the table was off level just a bit.... I think I could make it work, but I might as well turn this riser into a couple knife handles, I do have a couple Helle blanks laying around.  
Anyway,
I'll keep you all posted.
Mike

[Crooked Stic]

Ok while we are on this subject how do you guys dewax your wood? That would have been a good looker for sure.

[Bill Carlsen]

I know several fellows that made bows with ebony. It seems that is is a very dense and oil saturated wood that needs to be seasoned properly before use in bow building. It often checked and there were lots of issues with glue bonding.You really need to know what you are doing with it in order to make risers that will last.

[shantam]

first of all ebony can be a beast to work with,difficult to dry,oily.
i would try to repair it anyway.
cut out the phenolic with the bandsaw.
if you cut into the bocote or ebony you can make the
accent strips a tad bigger by adding a couple of veneers,colored glas,or another peace of phenolic.
whatever suits your needs interms of beauty.

good luck

shantam

[elk ninja]

I thinned out some smooth on and glued it all up.  It seemed to flow into the cracks real nice.  Clamped it all up with light pressure.  I am going to leave it clamped for several days, take them off and let it sit for another few weeks.  If it doesn't pull aprart then, it's a go.... at least thats the plan.
Mike

[Ray_G]

Mike,

Perhaps your table out of square, when sawing, has pulled this wood.  When I was building rifle stocks, I used ebony for the forend and grip caps.  The blocks were waxed.  I scraped them to remove as much as possible and then sawed a thin layer off.  Next came the acetone wash.  Prior to the epoxy, all surfaces were flattened and squared.  I never had a separation.  Granted we are talking smaller pieces but some were on heavy African caliber rifles.  The recoil would rattle your teeth!

Keep us posted.

Ray