First Delamination?

[Nathan Shaw]

Well, as the subject eludes I believe I had my first run in with a delamination issue. I’ve made many bows using this design without any issues that I’m aware of so I’m thinks it’s not a design flaw. I’ve used Huntsman epoxy for every bow I’ve made so also thinking that’s not the issue. I take meticulous notes and have been following the same procedures for glue up for some time now, again I don’t believe this is where it went wrong. I use a top and bottom form and have recently upped the pressure to 70lbs +/-. This is particular area I’m attaching a picture of is where I usually have to shim. It doesn’t explain the other random areas (that aren’t as obviously discolored). This was my first time using Osage as a veneer as well. The Osage turned a dark orange similar in color to an older Osage stave after it came out of the oven. I can not remember and did not take note on how long it was in the oven. Typical builds are 3-4 hrs. This is one area in my builds I have not been meticulous in. The time in the oven varies.

So my question is this. Any thoughts why? I’m adding a pic of the worst spot on the bow but it is cloudy on a few other random spots on the limb. I can’t feel the glass pick up where I think it’s delaminated, but it sure looks that way to me. If you have any thoughts I am all ears.

Thanks
Nathan

[Flem]

Sorry, that sucks! You changed two variables, that's where I would focus.
You upped the pressure, maybe too much squeeze out?
First time using Osage, maybe you did not degrease well enough?

Roy is one of the guy's you want to chime in on the Osage, I believe he uses it a lot. Personally I have never had any luck with osage. I never seem to get it prepped correctly.

[Roy from Pa]

Is that outer layer glass?

[Nathan Shaw]

Flem, I agree. I’ve made several runs with the higher pressure with no issues that I’m aware of. They where on black glass so now I’m a little concerned that I won’t know there’s an issue until it’s too late.

Roy, yes. It is .040 clear glass by BearPaw. It has 3 coats of a gloss finish and 2 coats of a semi gloss finish on it. It’s a 45# bow.

Nathan

[Nathan Shaw]

Flem, I forgot to add the second variable. First off I wear latex gloves when cleaning the lams. I use a stiff bristle brush for wood then wipe down with a clean cheese cloth and use denatured alcohol on the glass. I did not use chemical on any of the wood lams.

Nathan

[Flem]

Could be a problem with wood abuse. Maybe try wiping the lams next time.
Joking aside, I have not had much luck with oily woods. But thats my shortcoming. Do you blast the wood with compressed air after brushing?
 The only success I have had with difficult wood, is with Cocobolo. I sand Cocobolo to 80 grit, no solvent wipe. Usually sand all wood to 150 grit without issue.
Is your brush stainless? Might not matter, but when troubleshooting, don't discount anything.
Hang on, because lots of guy's here use difficult wood and will likely chime in.

[Nathan Shaw]

Those poor lams! I fixed previous statement. I do not use a stainless brush or compressed air. These lams where fresh off the thickness sander which I’ve had no problems with previously. I didn’t account for Osage being an oily wood. Maybe I should have gone with an 80 grit rather than my standard 120-150.

I really appreciate the input!

Nathan

[Roy from Pa]

I sand osage with 60 grit, then blow dust off with air compressor, then wipe with denatured alcohol on a clean cloth, then don't touch with fingers after that.

Looks like the delam is isolated to a smaller area.
Air hose gap maybe?

[Nathan Shaw]

I appreciate the insight fellas!

Any thoughts on the Osage going from the bright yellow as a raw veneer to burnt orange after coming out of the oven? Should I consider this normal?

[Nathan Shaw]

I also neglected to mention that these spots where not on the bow (under the glass) until recently. I shot the bow approximately 20 times then gave it my buddy. I don’t think it was shot much (less than 100 shots) in the last few months  then he brought it over to shoot the other day and that’s when I noticed it.

[kennym]

The Osage veneers I’ve used didn’t change color for a quite a while, gradually turning to a dark honey color. Sorry that’s not much help...

I’d be just guessing to say anything else.

[kennym]

Now that I'm on the computer with a bigger screen to look at the pic, is the glue line at riser bigger in the same spot?  If so you may not have gotten enough pressure to the back of bow in that area?

[Crooked Stic]

I see two things in the pic. The top part of the cloudy spot kinda fades in at the bottom has abrupt little stair step look. To me that looks like not enough pressure in that area. And the Huntsman glue being thinner may be your reason. Smooth on is all I have ever used. Not knocking Huntsman but thinner will have cosmetic problems if you are not careful. Maybe a little dip in the riser there.

[Bvas]

I agree with stic. The spot is well away from the fade area. Which tells me it was something with glue up pressure/gap. I don’t think it’s an adhesion problem.

I’m still a rookie, so my two cent is worth just that.

If it were me.....I’d try and wick as much CA glue into that area as possible. Then put a new overlay on to extend over that area. If the spot grows and extends past that point, you have a problem. If not, enjoy the bow.

[Nathan Shaw]

Well, I appreciate all the helpful insight. It all makes perfect sense. The last several glue ups I have put shims under the hose at the fades to insure a good tight fit. On occasion I have had to shim along the curved section of the riser and if my memory serves me right I had to put some shims on this one to ensure good contact. With using a metal pressure strip it makes sense to me that this particular area may not have had as much pressure applied to it due to shims on either side of it. I hope this is the issue. This is something I can definitely fix in future builds. If nothing else just to be mindful of.

Once I get home I’m going to look it over closely. I’m thinking there we’re a couple other spots of concern. I was a bit dejected at the time and just put this bow away and handed my buddy the bow I had just set got set up for me to hunt with.

Again, thank you all for taking a few moments out of your day to lend a helping hand!

Nathan

[Roy from Pa]

If you need a bow to hunt with,  I can send you a loaner for the season.

[kennym]

Same as Roy, I can send you one if you tell me the weight you use... Shipping would be cheap from MO to MO too.

[Nathan Shaw]

I appreciate it fellas but I have a couple to choose from. I have this 38# bow that I shot at tournaments this year that I shot pretty well. I’ve got in my head to hunt off the ground this year so on top of that I’m going to have to get them in close. It should be a solid challenge.

If I was going to be honest I’m not all that concerned with sticking a deer like I used to. I have a 14 yr old that has been hunting hard for the last several years that I would much rather see be successful. I’ve settled into my supportive roll over the years and leave the killing to the kiddos.

Thanks again,
Nathan

[Roy from Pa]

Nathan
 

[BigJim]

First things first... Oily woods are not an issue, nor do they require special care other than that they are dry!!!! You will find that experienced bowyers have no issues with the so called oily woods. That is because they understand the importance of dry wood!

Yes, veneers can hold moisture for at least a short period of time and most all wood suppliers will tell you " dry? oh yeah, it has been air drying for quite some time." They don't know and most bowyer don't really either except that they have had it for a while on the shelf and by then, it is dry.

I have a state of the art moisture meter and it is still an educated guess. With veneer, it is worthless!
Osage shouldn't change color that quickly. I've personally never had an issue with it. find it to be exceptionally easy to work with.

Personally, I sand with 60 grit with oily woods, or 60 grit with non oily woods or 60 grit with soft woods, or 60 grit with … well you guessed it, any wood. Now if i'm going to stain, I use 120 but my butt puckers when I think about it...however the drying of the stain/alcohol does open the pores and I'm hoping accepts the glue better too.

This is what I do, not that it is the right thing to do, but it works for me...or has. Higher air pressure is only possibly an issue if you sand with finer sand paper. Generally, we press the crap out of them. Sure I have had an issue occasionally, but have rarely been able to track down the problem because they are obscure.

Good luck, BigJim