Primitive Archer

Main Discussion Area => Bows => Topic started by: Manolovis on May 24, 2021, 10:15:00 am

Title: bamboo backing: wood glue or epoxy?
Post by: Manolovis on May 24, 2021, 10:15:00 am
Hi all,
bamboo flatten to 3.5 mm, stave  is nice and flat and oil free.... but what is best to glue with? wood glue or epoxy.
Thanks
Title: Re: bamboo backing: wood glue or epoxy?
Post by: Digital Caveman on May 24, 2021, 10:19:04 am
What kind of wood glue, what kind of epoxy, what are your gluing standards and methods?
Title: Re: bamboo backing: wood glue or epoxy?
Post by: PatM on May 24, 2021, 11:03:27 am
Generally, epoxy or at least one of the urac or resocinol types glues.  People do use TB 3 though.
Title: Re: bamboo backing: wood glue or epoxy?
Post by: BowEd on May 24, 2021, 11:39:36 am
Smooth on.
Title: Re: bamboo backing: wood glue or epoxy?
Post by: Pat B on May 24, 2021, 12:17:25 pm
I never had a glue failure with TBIII and have used it on Bamboo and hickory backings.
Title: Re: bamboo backing: wood glue or epoxy?
Post by: Eric Krewson on May 25, 2021, 09:27:22 am
Like Pat said it depends on what kind of epoxy, defiantly don't use the two ton type from the local Walmart. I have used Urac, Unibond and Smooth On. I have a friend that uses nothing but TB3 and has very good luck with it, he even says he can make heat corrections after glue up with no delaminating.

Good glues for bowmaking have a degree of flexibility in them after they cure, not so with double squeeze tube types. I tried Gorilla glue once, it failed in short order.
Title: Re: bamboo backing: wood glue or epoxy?
Post by: Dances with squirrels on May 25, 2021, 09:40:21 am
Glue choice should be made in conjunction with how you prep the gluing surfaces. If smooth and perfectly mated with no gaps, use something without gap filling properties like Titebond. If rougher, like sanded with 50 to 80 grit, use a good epoxy like Smooth On ea40.

I finish thinning and prep the glue surface of my bamboo with a toothing plane, and sand the core wood with 40-50 grit in my thickness sander. I use Smooth On epoxy.

The same concerns apply to adding pieces to the handle area to build thickness. I prep all those surfaces with the toothing plane blade and use Smooth On.

I have also made numerous heat corrections on bows glued up with Smooth On without incident.
Title: Re: bamboo backing: wood glue or epoxy?
Post by: Eric Krewson on May 25, 2021, 04:27:47 pm
I use a toothing plane as well to prep surfaces. I did heat correction on a static limb tip to move it over and center the string in the groove, the tip overlay was glued on with smooth on and fell off, I went back to Unibond.
Title: Re: bamboo backing: wood glue or epoxy?
Post by: Del the cat on May 25, 2021, 05:23:02 pm
I've had success with TBIII and Cascamite
Del
Title: Re: bamboo backing: wood glue or epoxy?
Post by: bownarra on May 26, 2021, 02:47:56 am
The data sheet (every glue has one if you just email the manufacturer) will tell you everything you need to know.
Title: Re: bamboo backing: wood glue or epoxy?
Post by: BoltBows on May 26, 2021, 04:49:18 am
Hi Manolovis,

Like everyone else is indicating: ''Best'' is relative to your preferences. I'll try to list some properties to help you with your choice :).

TB3 upsides:
- Cheap
- Easy & quick to apply, generally easy to work with.
- Strong, somewhat elastic glue that will definitely hold bows together.
- Clean glue lines are nearly invisible.
- Easy to clean.

TB3 downsides:
- ''Open time'' is limited to about 10 minutes (assembly time to 20)
- Requires a really tight fit and good even clamping pressure (The glue shrinks while it dries)
- Does stretch and doesn't hold reflex as well as epoxy in my experience...

Epoxy upsides: (I mainly have EA-40 in mind here)
- Long open time (up to 2 hours).
- Glue lines don't need to be as tight because it's thicker than PVAC.
- Can be heated to improve strength and performance.
- Gets thinner when heated, which can be useful for application.
- Holds reflex and curves very well.

Downsides:
- Pretty unhealthy stuff, don't want it on your skin. Also the vapors are bad.
- Expensive.
- Not easy to clean.
- Gets thinner when heated and so doesn't exactly fill gaps in that way...
- Generally requires more preparation time.
- Requires a heat box and decent setup if you want to optimize the results.

Hope this helps!

Jaap
Title: Re: bamboo backing: wood glue or epoxy?
Post by: Manolovis on May 26, 2021, 09:03:55 am
Thanks to you all!
I have tried to laminate once with pva before ( gorilla ) and the bamboo delaminated... i suppose my glue line was not perfect as i don t have the tools to make something neat. so ill try epoxy this time (west system). my glue line again is not perfect but still quite decent really. it will hopefully keep things together.
Title: Re: bamboo backing: wood glue or epoxy?
Post by: AndrewS on May 26, 2021, 09:05:04 am
I had best results with resorcinol glue (Bindan Cin). It is a glue especially for wood/wood .
Epoxy is more for wood / gfk (cfk)

Resorcinol is also no friend of your health.


What about hideglue. If you live not in a to humid climate it is a choice.
Title: Re: bamboo backing: wood glue or epoxy?
Post by: Eric Krewson on May 26, 2021, 10:40:27 am
I have not used hide glue for backing but have used it for sinew and wraps. It has worked for centuries so I am sure it will be fine. Although I haven't tried it I have heard the kind that comes in a bottle at the big box home improvement stores is to be avoided, something about additives.

I have use powdered hide glue and Knox from Walmart, I can tell no difference.
Title: Re: bamboo backing: wood glue or epoxy?
Post by: HH~ on May 26, 2021, 11:59:21 am
2 part epoxy specifically manufactured for laminating, No Question.

HH~
Title: Re: bamboo backing: wood glue or epoxy?
Post by: AndrewS on May 26, 2021, 04:08:52 pm
No question - but another thesis:

the epoxy is for laminating, but first for laminating glas, carbon and so on. It is also ok for wood/wood laminations.

Some kind of resorcinol is used for laminting wood to waterproof multiplex wood boards, other kinds are resistent against salty water and are used for wooden boats. Also some kinds of resorcinol are heat resistent until 170° / 180° C ( 340° F/ 355° F) and some kinds are good for that all.

In my personal opinion resorcinol is best for wood / wood.

... and hide glue (may plus a wrapping of sinew, rawhide or thin bark) is the traditional way.
Title: Re: bamboo backing: wood glue or epoxy?
Post by: HH~ on May 26, 2021, 06:12:14 pm
Ok, i will play

For laminating WOOD!

H.H

Title: Re: bamboo backing: wood glue or epoxy?
Post by: AndrewS on May 27, 2021, 06:47:24 am
First play with your computer and read something about the different glues....


Epoxy is a plastic resin. It can be used in many ways - as an adhesive, as a coating, for almost all materials (concrete, stone, steel, wood, for flooring) and as an adhesive matrix for modern fibers (glass, carbon). It does not swell and is therefore not joint-filling, it needs heat to cure optimally but it resists heat in the cured state only to a limited extent.

Cascamite is a urea adhesive for exterior wood and also for boat building.  Cascamite has a light glue line.

Resorcinol is an adhesive especially for woodworking / structural woodwork (especially for exterior woodwork, boatbuilding and construction with resinous and oily exotic woods) based on resorcinol and phenolic resins with formaldehyde. Always easily recognizable by the dark (red or brown) glue line.
Recorcinol glue is easily joint-filling and very resistant to high temperatures.

None of these glues are made specifically for bow making, because the market is very small after all.
For laminated bows made of modern materials (wood core, glass and/or carbon backing and facing), epoxy has established itself as the universal glue.
Cascamite and Resorcinol are only optimally suited for wood and therefore also for wood/wood laminations (professionally for waterproof glued multiplex boards (screen printing plates)). 

I have the best experience with Resorcinol myself and it is my first choice for glueing wood. It is gap filling and I can temper the bow with the heatgun after glueing without porblems (with epoxy I have had often problems at this point). The open time of the Resorcinol I use is 90 minutes and thats optimal if you had to fix the lams by clamps.

I have no experience with Cascamite so far.

I also have experience with Epoxy and in my opinion it is not as good as Resorcinol for wood/wood joints.



Title: Re: bamboo backing: wood glue or epoxy?
Post by: HH~ on May 27, 2021, 09:19:23 am
Thats all well and good here in USA we big companies who make all kine adhesives. Some make two port epoxies that were designed for all sorts of laminating ie putting space shuttle tiles on (yeah we go to space a bunch) anyWho's. Where was I? Oh, yes, after producing these adhesives they have some that were found to work very well with wood Lams or porous materials, (wood, glass, some ceramics) some have charracteristics that work well with laminating. One is they do not shrink .0001 or less when cured. . . . . Ding Ding Ding and they were found by bow makers to work very well. I'm sure you'll send data spec sheets for us and tell us whats best for even big bow Companies like Black Widow and Bob Lee. I know what they use and it works.

Oh yes, to be clear as to your old PM to me,   HH~ does not refer to Heil Hilter

HH~
Title: Re: bamboo backing: wood glue or epoxy?
Post by: Marc St Louis on May 27, 2021, 09:35:04 am
Thanks to you all!
I have tried to laminate once with pva before ( gorilla ) and the bamboo delaminated... i suppose my glue line was not perfect as i don t have the tools to make something neat. so ill try epoxy this time (west system). my glue line again is not perfect but still quite decent really. it will hopefully keep things together.

I wouldn't use the Gorilla pva glue for anything but simple low stress gluing as it is low quality
Title: Re: bamboo backing: wood glue or epoxy?
Post by: bassman211 on May 27, 2021, 10:07:44 am
Smooth on has never failed me. It is my go to for all my glue jobs pertaining to bows. Even tip over lays. Until it does fail I have no interest in trying any thing else. If it works it works.
Title: Re: bamboo backing: wood glue or epoxy?
Post by: AndrewS on May 27, 2021, 11:58:16 am
Thats all well and good here in USA we big companies who make all kine adhesives. Some make two port epoxies that were designed for all sorts of laminating ie putting space shuttle tiles on (yeah we go to space a bunch) anyWho's. Where was I? Oh, yes, after producing these adhesives they have some that were found to work very well with wood Lams or porous materials, (wood, glass, some ceramics) some have charracteristics that work well with laminating. One is they do not shrink .0001 or less when cured. . . . . Ding Ding Ding and they were found by bow makers to work very well. I'm sure you'll send data spec sheets for us and tell us whats best for even big bow Companies like Black Widow and Bob Lee. I know what they use and it works.

Oh yes, to be clear as to your old PM to me,   HH~ does not refer to Heil Hilter

HH~

Sure, BW and Bob Lee use epoxy to glue their fiberglass laminates to backing and belly, what else.

Not sure if I will send any data sheets....

Also, I'm not sure if the epoxy was developed by aerospace and rocket scientists in the US. I think epoxy was developed by Paul Schlack (Germany) and Pierre Castan (Switzerland) in 1930s, but that's another topic...
Today, epoxy is produced worldwide by various companies.

As I have written several times, epoxy also works for wood/wood joints.
However, there are adhesives that work better for me, that's all.

I have had laminated wood bows (several laminates Osage with a backing of bamboo) from American bow makers with the dark glue line typical of resorcinol glue. That was in the 1990s.
As far as I remember Urac was quite a popular glue among bow makers at that time ( Didn't Dean Torges recommend it too?).
I don't know if it is still in demand today, or if it is even produced today?


And sure I will not call you little Adi in the future....

Title: Re: bamboo backing: wood glue or epoxy?
Post by: Dances with squirrels on May 27, 2021, 12:30:10 pm
I believe Urac 185 is now Unibond 800.

I've used them, and liked them.... Resorcinol too, but I liked Resorcinol for Z splices under the handle leather where I couldn't see it. I like invisible glue lines. But Smooth On ea40 works fine for splices too. Smooth On is great for wood to wood, wood to glass, wood to horn, and more. It's my go-to glue for bow work, except for special occasions where hide glue or thin viscosity CA is more appropriate. I got tired of having so many different glues around, some going bad before I could use them. No such worries now.
Title: Re: bamboo backing: wood glue or epoxy?
Post by: HH~ on May 27, 2021, 12:30:52 pm
Yep, bier, H Bombs and jet engines.

Glue not so much...  (f)

HH ⚡️⚡️
Title: Re: bamboo backing: wood glue or epoxy?
Post by: AndrewS on May 27, 2021, 01:28:01 pm
@HH~

All right, I know you know where Barthel gets it 8)


P.S. A guy named Otto Hetzer from Weimar has developed the casein glue at the beginnning of the 20th century (that was a revolution for wood construction)
... epoxy has developed in 1930iger in Europe (Germany and Schwitzerland) and resorcinol  glue has developed in 1942 in the USA....

and cause that's the fun of life: beer is not german innovation. I think the Sumerians and Egyptians
 have had beer a few thousands years before.....
but since 1862 The company Merck from Germany sells Benzoylecgoninmethylester (Cocainum) developed by  Albert Niemann (Göttingen, Germany) or a german guy named Friedrich Gaedcke. May be this was the stuff that make Coca Cola famous... (f)
And since 1898 Bayer sells diacetylmorphine that is developed by the work of the british Charles Romley Alder Wright and Felix Hoffmann (Bayer) - this is the stuff for heroes...

last but not least: moreover, i believe that national socialist coding is recognized as such in the u.s. as well.


Title: Re: bamboo backing: wood glue or epoxy?
Post by: Tommy D on May 31, 2021, 04:49:05 am
Does anyone who does use epoxy resin to glue backings add any fillers? Like microfibres? I know that it is often recommended in wood boat building applications to do a clear coat of the two mating surfaces (preferably after they have been warmed slightly so the absorb the resin) and then a thin “mayonnaise” consistency of epoxy mixed with a filler is added. Obviously this is helpful where mating surfaces aren’t perfect, but I wondered if it adds any strength. One issue with epoxy believe is you can apply too much pressure and have a dry joint.

Would be interested in others experiences?
Title: Re: bamboo backing: wood glue or epoxy?
Post by: PatM on May 31, 2021, 08:20:25 am
That is for when you are bonding when using  an epoxy not specifically formulated solely  for bonding.  It's thinner and more geared for the process of laying on glass and coating.  You certainly can add thickeners and use it for gluing backings.  DC on here did that for all his bows.

  The epoxies typically used for gluing on backings by most come pre-thickened and need no additives.
Title: Re: bamboo backing: wood glue or epoxy?
Post by: Tommy D on May 31, 2021, 09:02:16 am

  The epoxies typically used for gluing on backings by most come pre-thickened and need no additives.

Thanks - somewhere on Primitive archer I read someone post that these “thickened” epoxies are not as strong as the unthickened versions. That’s why I was curious.
Title: Re: bamboo backing: wood glue or epoxy?
Post by: HH~ on May 31, 2021, 11:17:07 am
The advantage to the two part adhesives is they do not shrink during curing. So if you have a small variation in a glue line as long as you fill it and its not right in fade it will fill that void. With a wood glue it shrinks a CHIIIIT Ton. Have a bad glue line your asking for a problem right off.

Hedge~
Title: Re: bamboo backing: wood glue or epoxy?
Post by: PatM on May 31, 2021, 11:44:38 am

  The epoxies typically used for gluing on backings by most come pre-thickened and need no additives.

Thanks - somewhere on Primitive archer I read someone post that these “thickened” epoxies are not as strong as the unthickened versions. That’s why I was curious.

 Not enough to worry about if true. 
Title: Re: bamboo backing: wood glue or epoxy?
Post by: freke on June 01, 2021, 04:41:16 am
A have one project a head, bamboo/yew so I read this with intrests.

Regarding Epoxy;
Are there any alternatives to EA-40?
What makes the epoxy in smaller package in iron stores not suitable, for example I found one that had a couple of hour open time that at least would give me enough time, but what else properties to look for?

Thanks Jonas
Title: Re: bamboo backing: wood glue or epoxy?
Post by: Del the cat on June 01, 2021, 05:08:13 am
I think the question has been answered... to ask why some other unspecified adhesive ins't suitable is a bit of an open ended question*.
Read the data sheets, compare the figures with those for the stuff that has already been recommended.
If you find one that looks like it might work, try it if you are willing to risk the time and effort... then report back to us as I'm sure we'd like to find another reliable easy to buy affordable adhesive.
I, for one have spend countless hours reading engineering data sheets from some of the big engineering supply firms, E-mailing their technical/applications departments etc. (usually on company time  :o ::) ). The result being I recommend Cascamite or TBIII, I didn't really think I'd be asked to explain my recommendation, but I'm happy to. I expect a lot of others have been through the same search as me.
Del
* One answer is quality control, some own brand stuff bay be from random suppliers, may be past it's shelf life, may not all be from the same batch and may be totally different next time you buy it. I use cheap 5 minute own brand epoxy for non critical, applications only.
Title: Re: bamboo backing: wood glue or epoxy?
Post by: Tommy D on June 01, 2021, 05:18:03 am

  The epoxies typically used for gluing on backings by most come pre-thickened and need no additives.

Thanks - somewhere on Primitive archer I read someone post that these “thickened” epoxies are not as strong as the unthickened versions. That’s why I was curious.

 Not enough to worry about if true.

This made me curious enough to look at the TDS for West System G-Flex vs West 105 ... and there does seem to be quite a difference in strength between the two ...

(https://i.imgur.com/rkfPhp1.png)
(https://i.imgur.com/xCujYvD.png)
Title: Re: bamboo backing: wood glue or epoxy?
Post by: PatM on June 01, 2021, 12:53:10 pm
Those differences are  mainly due to other reasons though.  Considering that G-flex is an excellent bow glue, your concerns are unfounded.

 A good compromise is to mix G- Flex and 105 half and half.  That will put you at a more typical bow building epoxy range if it makes you feel better.