Best & Strongest wood glues.

[irishrover1970]

 

 

Hello all. I am sure this topic “or a version of it”is here on this site somewhere ,but I wanted to be more specific. I just had a glue joint crack off a plank I had glued to a bulkhead when I applied just a little pressure, (not much at all) . I used“titebond translucent”glue. It cured for over 24 hours.Was my first time using it and maybe my last! My question is are the other titebond gules better then this stuff? I also have some testors wood glue cement stuff that I’ve yet to try. Is that any good? I’d like to find a super strong glue that can hold up like it should. Any suggestions would be greatly appreciated. Thanks...

[mtaylor]

You'll get lots of answers as to everyone's preference... including mine..     

 

I use either Elmer's Glue-All or Wood Glue mostly and some CA.

[Jaager]

When the bonding surfaces are aligned correctly, PVA forms a bond that is stronger than the wood fibers.  PVA comes in many flavors, the two major divisions are white and yellow.  I do not know the strength differences - if any.  For your purpose, the translucent may not have been as good a choice of PVA as you could have made. 

That said, the weakest of wood to wood bonds is when end grain is involved.  It is possible that the edge of the plywood mould had a lot of end grain as the bonding surface.  Pine or Fir plywood would be a weak surface with large pores.

The strength of a PVA bond is proportional to clamping pressure.  The closer the two surfaces are, the stronger the bond.  The upper limit is when the pressure deforms the outer surface of the wood being clamped.  PVA forms long interlinking chains as it cures.  In 24 hrs, the bulk of the chemical reaction has occurred. 

Rather than convicting the adhesive, examine the surfaces-  how close were they?  how much of the mould surface was actually in the same plane with the plank?  Beveling is a skill.  In POB, it is difficult to apply enough pressure.  Some POB practitioners "fatten" the space between the moulds with additional wood to supply more surface area and allow for one layer of planking to be sufficient.

Additional wood pieces can be cut and fitted to the inside after the plank has been fitted, but since no real force can be applied, the bond will not be strong.

[kurtvd19]

Titebond Translucent has essentially the same properties as their Original, II and III glues with shear strength right between the original and II at 3,550 psi - more than adequate for model purposes.  The original, II and II strengths are all stronger than the wood once the joint is cured - meaning that the wood should fail before the glue.  Of course the tightness of the joint as others have mentioned is very important.  But from a strength aspect these is hardly any difference between the glues.  I suspect the joint itself was the issue not the glue.

Titebond has very extensive use/application and properties descriptions on their website.

Kurt

 

[Jaager]

If your moulds are plywood, the bond can be improved by pre-treating the end grain sections.  For Hard Maple and Black Cherry, I pre- treat with a 50-50 PVA - water to fill the pores.  For plywood, I would go up to 4 - 1 or 5-1 PVA - water as the openings are much larger. Just avoid any glue buildup on the surface.  24-48 hrs setup time.

[No Idea]

Was the bulkhead laser cut?  Did you remove all of the burnt edge first. The ash that’s left can stop a decent gluing joint 

[vaddoc]

As others said, PVA works when clean surfaces are in close contact. All PVAs will perform adequately, no huge difference one brand from the other. (There are differences between aliphatic and plain white PVA)

If there are gaps or close contact is not certain, I use epoxy thickened with talk powder (or wood dust, I ve even used ground coffee, all worked the same). Epoxy alone is too brittle and in my experience these joints can fail. 

 

Epoxy is brilliant stuff but can be messy. Best not to come into contact with skin as sensitivity builds up over time. I use single use syringes, pots and gloves, it is an acquired skill. Unlike PVA, epoxy resins can be very different, some hard and some really flexible when fully cured. I now use only zpoxy which is fantastic. 30 min as glue, finishing resin for laminating.

 

Regards

Vaddoc

[Bob Blarney]

As stated above, a close mechanical fit is essential for the best bond with any glue.  One of my favorite glues is old-school hot hide glue.  It is quite strong yet reversible, is usually a good color match, and does not not interfere with any kind of finish.   The key is mix it properly and apply at the correct temperature, about 145F.