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Main Boards => The Bowyer's Bench => Topic started by: Susquehannariverarcher on May 05, 2024, 10:29:05 AM
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Glued up an all zircote glass long bow. And when I checked it using the push pull method the belly glass came right off. I could peel it off like tape.
I used a lot of 1:1 mixed ea 40, weighed both parts and everything. Put it in the heat box like I normally do, etc.
After talking to someone through here I'm wondering if using acetone on the zircote caused the oils to lift or something. I haven't used acetone on the veneers on my 2 previous bows. But these one got pretty dusty in storage.
Also glue up is my part I'm struggling the most with. I definitely have some short comings in my form and I'm going to build a new one. But I'll take any and all glue up tips.
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Don't use Aceton on "oily" woods.
If you have dirt or dust in your veneers, sand them and blow of the dust.
Mix Smooth on 2:1.
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Mix by volume not by weight . Part B is lighter than part a so you would get too much of part B by weighing 50 -50 . Acetone works to clean oily woods I use it everyday .
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I never use acetone on veneers. How old is your epoxy? I mix by volume, be sure and mix it really well. Several years back we had some bad ea 40 sure we aren't having a repeat
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Epoxy is new. And good to know about doing it by volume. I'm curious on why only one part delaminted.
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I never use acetone on anything to glue up. Brush or blow off(clean air) , I use 40 - 50 grit on lams and riser parts, I know veneer sheets I've bought seem pretty smooth, so last one I did with those, I clamped one end and block sanded with 50 , pushing away from clamp always ,if you pull back you break a veneer(I know this!!)
EA 40 is pretty easy , as long as you don't get too much of the hardener in it. I measure with plastic cups and go with a little more part a than b.
You can go as much as 2A:1B but I never go that much.
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Oh, Chad Holm was shooting a bow when he was here to hunt once ,he peeled glass off of due to streaks and put new glass on. Said if you warm the glass at tip , get a knife under it and warm it a little as you peel, you can take it right off. I'd see if I could save it by removing glass, sanding the glue on lam and glass with a block to keep even , and run her thru the form again. Might be out a bit of glue if it doesn't work...
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Oh, Chad Holm was shooting a bow when he was here to hunt once ,he peeled glass off of due to streaks and put new glass on. Said if you warm the glass at tip , get a knife under it and warm it a little as you peel, you can take it right off. I'd see if I could save it by removing glass, sanding the glue on lam and glass with a block to keep even , and run her thru the form again. Might be out a bit of glue if it doesn't work...
I might have to.give that a try. And thanks for the information. The rest of the glue (all from the same batch) seemed to hold up but I'll give a try back in the press.
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I clean my glass with acetone. Never on wood. Like Kenny said always use more resin than harder by volume.
I have never got too excited about the mix as long as more resin than hardener. Heat mine up to about 135 4-6 hours depending on temp at the time let them cool and good to go.
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Crooked stic do you do anything different with oily woods? My last bow was curly maple and all went well.
When I inspected the failed bow this afternoon. The glass separated very cleanly and left a very smooth layer of epoxy on the veneer.
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I too always scrub the glass with acetone but never any woods.
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Glued up an all zircote glass long bow. And when I checked it using the push pull method the belly glass came right off. I could peel it off like tape.
What is the push pull method?? :dunno:
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Glued up an all zircote glass long bow. And when I checked it using the push pull method the belly glass came right off. I could peel it off like tape.
What is the push pull method?? :dunno:
Yep. It happened immediately, very little pressure.
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Here's a bad picture of what happened. Dropped my phone the other day
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Here's a bad picture of what happened. Dropped my phone the other day
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If your MC is good tĥen wood just needs to be fresh sanded and blowed off with air I can't use the rosewoods they break me out.
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Ok good to know stic. Always learning something...
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Glued up an all zircote glass long bow. And when I checked it using the push pull method the belly glass came right off. I could peel it off like tape.
What is the push pull method?? :dunno:
Just realized I read this wrong. And push pull is like the stringing method. But i didn't have a string on it. I heard someone call it that once. Idk know the actual proper term for it.
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It seems to me, that if the glass peeled off “cleanly and left a very smooth layer of epoxy on the veneer” the problem was with the glass and not the wood. Are you 100% certain you wiped down that glass? That would be the question I would be asking myself in the same situation.
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It seems to me, that if the glass peeled off “cleanly and left a very smooth layer of epoxy on the veneer” the problem was with the glass and not the wood. Are you 100% certain you wiped down that glass? That would be the question I would be asking myself in the same situation.
I think I would agree with this post. I always clean glass only with acetone. Never the wood. Freshly sand, and use a brush just prior to lay up. I mix my EA 40 about 2/3rds resin to 1 third hardener, heat it before mixing, then mix throughly with my drill and a paddle bit for a minute or so. Kirk.
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Glued up an all zircote glass long bow. And when I checked it using the push pull method the belly glass came right off. I could peel it off like tape.
What is the push pull method?? :dunno:
Just realized I read this wrong. And push pull is like the stringing method. But i didn't have a string on it. I heard someone call it that once. Idk know the actual proper term for it.
Think you are referring to "floor tillering".
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By chance did you mistake and glue the shinny side,?
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I use a hard brush like this
https://www.lowes.com/pd/Project-Source-Poly-Fiber-Stiff-Tile-and-Grout-Brush/5014195395?cm_mmc=shp-_-c-_-prd-_-hdw-_-ggl-_-CRP_SHP_LIA_HDW_Online_E-F-_-5014195395-_-local-_-0-_-0&gad_source=1&gclid=Cj0KCQjw_-GxBhC1ARIsADGgDjvHgeIYcZlLmJWbda43JkqehAdqcAS6TQ-B4p4b6CynDLwijcTA9lUaAjwHEALw_wcB&gclsrc=aw.ds
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Ok yeah I guess it would be floor tillering. I was just getting a feel of its weight. And I'm pretty sure I cleaned it with acetone but I may have missed it. I'm nearly sure I glued the rough side down. But I'm prone to mistakes. I'll check later and kick myself in the butt if I messed that one up!
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Everyone here has made their share of mistakes! Unfortunately it is a big part of how we learn.
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Wouldn't be fun if there wasn't a challenge and mistakes. But I hope one of these days it gets a little easier ha
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I keep looking at the pic of the delam, did you flex that before side tapering? That might put a lot more stress at fades with full width limb.
Not saying that caused it , just wondering…
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I keep looking at the pic of the delam, did you flex that before side tapering? That might put a lot more stress at fades with full width limb.
Not saying that caused it , just wondering…
I did. But I don't think it was that. It was instant and started at tip end. I bet I could've peeled the glass off like a band aid m before flexing if I would've noticed. I'll get a better picture of what's left on the veneer side.
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Ok just wondered
Stuff like that drives me nuts (more nuts than already)
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Scuffed it all up with some 40 grit, glued it up, put it back in the form/box. Guess we'll see if it can be salvaged.
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I know Chad did it and hunted with it! Hope it works!!
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I always wipe down with acetone and haven't had issues with glass peeling off. I do put the lams and glass in the bow oven for 10 minutes or so after wiping them down to make sure the acetone has evaporated. Best practice is to follow the instructions from smooth-on for this product. Here's a link to the full instruction sheets. Hint: They recommend wiping all surfaces with acetone after sanding with 120 grit.
https://www.smooth-on.com/tb/files/EA40.pdf
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Thanks bird bow I'll give that a read!
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I know Chad did it and hunted with it! Hope it works!!
Pulled it off the press just now. Seemed like it worked, at least for now.
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Hoping so!! :pray:
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Any idea what causes these little imperfections? They seem to be between the glass and veneer. This on the back of the bow not the glass I just reglued. Haven't pulled the tape off to check the belly yet.
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looks like air bubbles to me....
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are you applying the glue to both mating surfaces-{glass & lamination}? I will usually get more squeeze out than, maybe not enough glue? :dunno:
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Kirk of they were air bubbles would they go all the way to edge of the limb and leave visible little air holes in the glue? If so I don't have that.
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are you applying the glue to both mating surfaces-{glass & lamination}? I will usually get more squeeze out than, maybe not enough glue? :dunno:
I am applying to both surfaces. This picture is after glueing just one layer on. When I pull my bows out of the press I can hardly see them, they look like they're covered in stalactites worthy of NatGeo.
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They do look like air bubbles, how much pressure used?
Also some guys have had the lams to gas off if not dry enough. One bowyer says to let the bow sit in press for a couple hours before heat, to let the epoxy start to fire off. This way it doesn't heat the lams too soon and make the wood let gas off. :dunno:
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50 lbs. Should I be going more? Is pressure the main cause of air bubbles?
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I've used from 50 to 70 so I don't think that would be it.
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Ok. Does this lead to failure or is it more of cosmetic thing?
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It is good to air up your hose in increments with a few minutes between each increment.
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Ok. I was doing increments but definitely not that long in between.
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Bearpaw glass or Gordon's? I let mine sit about 30 minutes before going in the hotbox.
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Bearpaw
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I believe there are two reasons for getting those air bubbles, insufficient pressure in that particular area and not letting the lams gas off. Check the gap in your form in the area where the bubbles occurred if it is larger that the length of the gap between the rest of the form this could be the issue, and like Kenny said I always let my limb sit in the form for about an hour before putting into the oven, haven't had any issues with air bubbles since doing this practice knock on wood.
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They're pretty consistent throughout the limb. I'm guessing that might mean not enough pressure throughout? There is a chance I may not have used as much pressure as I thought.
Depending on when the mail gets here I should be gluing another one up today. I will try letting sit in the form. Unfortunately I won't be using clear glass. So I'm guessing it will be hard to tell.
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What is the gap distance?
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I've been airing up to 50psi and then in the oven it brings it up to 60ish, you don't want to use too much. Don't ask how I know.
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Bearpaw is not noted for clarity and quality any longer.
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Jess what do you recommend?
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Gordon's is more consistent with both strength and clarity. Seems bearpaw quality really sliped the last few years. I no longer use it
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Thank you!
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Gordon's is more consistent with both strength and clarity. Seems bearpaw quality really sliped the last few years. I no longer use it
Bear Paw glass hasn't been synonymous with consistency or quality for many years. It does seem to hold up ok after its laid up though.... if you were building low budget production bows where you are not seriously concerned with hitting a certain draw weight, you can save a lot of money buying it in large rolls..... Stick with gordon glass for better consistency. But even Gordon glass has imperfections in clear glass. I do not guarantee the clarity of clear glass over veneers for my customers. Darker colored veneers show more imperfections than lighter colored veneers. Some come out flawless, others have streaks or cloudy spots. Curing at lower temps is always a good plan with clear glass, as higher temps often create air bubbles.... food for thought.... Kirk