Author Topic: Glues  (Read 8674 times)

biker

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Glues
« on: April 05, 2009, 08:43:30 PM »
Hi All;
I have made several wooden clocks over the last couple of years and they have all worked quite well, that is until recently. My first clock has started to fall apart, the glue is coming undone.
first the laminated drive pulley seperated, and now some of the other joints have started to come adrift.
Could someone please tell me what the best glue is to use so that the clocks dont fall apart after time?

Offline steve323

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Re: Glues
« Reply #1 on: April 06, 2009, 09:17:15 AM »
What type of glue are you using? 

I can't imagine that something like Titebond II or III wood glue would come apart if there is a reasonable contact area.

Steve

Offline BrianC

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Re: Glues
« Reply #2 on: May 10, 2009, 05:49:27 AM »
Unibond 800, an urea resin formaldehyde glue, was recommended for laminating at a woodworking show I went to - the instructor laminated a horse collar which isn't flat and will have more stress than anything we do.  Unibond 800 has reasonable assembly time (which is adjustable by changing the mix or heat), rigid glue line, low shrinkage and cleans up with water.  The only fault is that it can go right through thin pieces (like veneer), but this is preventable (and it can be dyed) and means the glue gets a good grip on the wood.
https://secure.burgessinc.com/vacupress/veneerglue.htm
BrianC

Offline bobledoux

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Re: Glues
« Reply #3 on: May 16, 2009, 05:51:45 PM »
Check the actual specification for glue pressures.  I've used traditional urea resin formaldehyde glues for aircraft construction and they specified at least 75 pounds per square inch for clamp pressure.  The company ad says it can be used at low joint pressure, but just what is "low?"

What were you using for wood? Some oily woods require special treatment to get good bonds.

Offline BrianC

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Re: Glues
« Reply #4 on: May 17, 2009, 07:23:38 PM »
The supplier of Unibond 800 specs it for veneering and for furniture and cabinets as well as the use of vacuum pressing systems and, although they don't give the clamping specs, I doubt it would be 75 PSI.  Also, the use of vacuum pulls the glue into the pores of the wood and so should increase the penetration, which isn't a problem - in fact they sell a blocker because some customers complained it penetrated through the veneer.

Wow, that's a lot of clamping pressure, it wouldn't take a very large piece to go into a bazillion tons of over-all pressure.

As far as the wood, were you directing that to biker or me?  So far I've used Unibond on Maple veneer and the instructor said he used it on several types, but, yeah, I know about oily woods, I'm planning on using Lignum Vitae (a VERY oily VERY dense wood) for some parts of my clock.  I'm planning on wiping or washing it with acetone and using keys/pins, as well and assuming I'll need to test to verify bonding with what ever I use.

Brian
BrianC

Offline Andrew Roberts

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Re: Glues
« Reply #5 on: March 29, 2015, 07:02:38 PM »
Hello all.