Replies

1. 
   Michmesquite | Sep 21, 2004 12:04am | #1

   Poly glue does not fill gaps with any strength. There are quick set epoxies out there that are much better, and the epoxies can be loaded with dust from the same wood species to give a nearly invisible glue joint, even if not tight.

   I personally like and use the System Three products but there are other good manufacturers.

   _________________________________

   Michael in San Jose

   "In all affairs it's a healthy thing now and then to hang a question mark on the things you have long taken for granted." Bertrand Russell 

2. 
   SgianDubh | Sep 21, 2004 12:23am | #2

   lumo, I don't understand the request to use polyurethane glue for the sake of speed in any type of furniture let alone antiques-- it takes several hours to cure, preferably cramped up overnight, so little or no gain there on the speed front.

   It's a less than ideal choice for veneering in my opinion due to its tendency to push mating surfaces apart during the cure which involves foaming-- so voids are all too likely veneer application even with a good bag press.

   Apart from the fact that the Georgians, Victorians, etc., didn't assemble furniture with polyurethane glues in the first place, because it was only invented 2 or three decades ago, which leads to questions relating to destroying an antiques integrity and value, polyurethane is not a good gap filling glue for chair joints.  Yes, it does fill gaps, but it fills the gaps with fluffy foam which has little or no strength in and of itself.

   It's a useful glue type for many applications if used correctly, and is very handy around oily woods for example. Of all the wood glues I've used it's the type I find fails most often in panel edge gluing jobs.

   You're right to remain sceptical of the benefits of polyurethane glue for the applications you describe. I wouldn't countenance its use anywhere near a valuable antique except in very special circumstances, it can't make up for deficient chair joinery, and it's about the last type of glue I'd use on a veneering job. Slainte.

   RJFurniture

1. 
   Becks | Sep 21, 2004 12:40am | #3

   Exactly my point, fluffy foam !!, that is what makes me cautious about the stuff. I shall keep up the fight not to use the stuff. We do work on some very expensive items and when i was told to use it i ignored the pot which had been placed on my bench and carried on using scotch , 200+years cannot be wrong. The comment on oily timbers is welcome. Thank you for replying .  Lumo

1. 
   HowardAcheson | Sep 21, 2004 01:37am | #4

   One other point to add to Richard's comments. Poly adhesive does not adhere will other adhesives. In other words, the joint must be cleaned to virgin wood. I would not consider poly glue as a restoration adhesive.Howie.........

2. 
   lwj2 | Sep 26, 2004 09:06pm | #12

   I've used the polyurethane glues to edge join boards for table tops. It works well there, makes a nice tight bond with properly jointed boards.

   Won't use it for any joint work that may require dis-assembly at a later date. If set properly, it is stronger than many woods, hence the wood will fail before the glue does. Not a help when you're taking something apart.

   I assume Scotch glue is what I call hide glue. That's what I use on anything else other than jointed boards.

   Regards,

   Leon Jester

   Roanoke VA

3. 
   JohnWW | Sep 21, 2004 02:42am | #5

   With just a few exceptions for special situations, such as oily woods, there are several other types of glue that would be better than poly in the applications you discussed.  Whoever is pushing you to use poly is not very knowledgeable about the glues available for woodworking.

   John W.

1. 
   Elcoholic | Sep 21, 2004 11:03pm | #6

   After PVA, poly was the first adhesive I used for outdoor projects and even some bent laminations with good results.  Especially with teak and cocobolo.  In the intervening years I have discovered and become very comfortable with West Systems Epoxy (You just have to love those metering pumps!) and Weldwood plastic resin glue and would use those mostly where I used to use poly.  Another glue type/brand not often mentioned is vinyl glue as is RooGlue which is a melamine adhesive.  I like it for prefinished work (chairs) because it wipes off easily with a wet rag and dries clear.  If it'll cement (not weld as in a solvent based adhesive) melamine it seems it way do a good job in a less than glue free joint.  I can't say how strong it will be in a restoration, but as I use it, it's just insurance (suspenders) in a well fit and pegged M&T joint (belt) anyway.  You may want to give it a try.John O'Connell - JKO Handcrafted Woodworking

   The more things change ...

   We trained hard, but it seemed that every time we were beginning to form up into teams, we would be reorganized.  I was to learn later in life that we tend to meet any new situation by reorganizing; and a wonderful method it can be for creating the illusion of progress while producing confusion, inefficiency, and demoralization.

   Petronious Arbiter, 210 BC

4. 
   hotrod | Sep 22, 2004 03:14am | #7

   Do your patrons and future furniture restorers a favor and keep using hide glue.  Hide glue can be easily reconstituted with heat and moisture for veneer repair, easily heated and softened for dismantling of chairs or case goods, and does not have to be completely removed from a joint for repair with new hide glue.  The craftsman of old were not so worried about the bottom line as they were about giving fair value and hoping their work would outlast them!

   If you want a permanent veneer adhesive that is easy to work with try Unibond 800 sold by Vacuum Pressing systems.  The glue is essentially a urea-formaldehyde with easy working characteristics and a reasonable open time. 

   RJ

1. 
   Becks | Sep 22, 2004 11:22pm | #8

   Thanks all for the replys , some of the other glues mentioned will be sold under other names so i will search them out .I love using scotch because of its history and flexibility. and as for "the foamy stuff" it will sit on the corner of my bench for some time. 

1. 
   JohnWW | Sep 23, 2004 12:17am | #9

   If it sits on the bench for very long, just a month or two, it will harden in the bottle and then you can throw it away guilt free.  If you want to hurry it along, breath into the container for a moment every day, the moisture from your breath will hasten the hardening wonderfully.

   John W.

   Edited 9/22/2004 8:55 pm ET by JohnW

2. 
   Elcoholic | Sep 24, 2004 10:42pm | #11

   "The craftsman of old were not so worried about the bottom line as they were about giving fair value and hoping their work would outlast them!"

   Ah yes, a very nice bit of romanticized history, at least when it comes to glue.  They used what they had be it rice, fish or hide, plane and simple.

   That's analogous to looking at a 100 year old bridge and concluding rivets are better than arc welders because they were "true" craftsman.John O'Connell - JKO Handcrafted Woodworking

   The more things change ...

   We trained hard, but it seemed that every time we were beginning to form up into teams, we would be reorganized.  I was to learn later in life that we tend to meet any new situation by reorganizing; and a wonderful method it can be for creating the illusion of progress while producing confusion, inefficiency, and demoralization.

   Petronious Arbiter, 210 BC

5. 
   jackiechan | Sep 23, 2004 04:56am | #10

   Lumo,

   Here is a link to a previous Fine Woodworking article - A Working Guide To Glues.  It gives a breakdown of all the different glue types, their adhesive properties, and the appropriate applications in which they should be used.

   http://www.taunton.com/finewoodworking/pages/w00010.asp

   Dan Kornfeld, Owner/President - Odyssey Wood Design, Inc.