Replies

1. 
   bill_1010 | Aug 05, 2004 06:37am | #1

   If memory serves me right, its to extend the open time of the glue.

1. 
   joinerswork | Aug 05, 2004 03:17pm | #4

   WmP,

   Well that wouldn't be a bad thing for covering a tambour, either. I'm using grade 135 glue, for slower gelling time.

   Thanks,

   Ray

2. 
   UncleDunc | Aug 05, 2004 07:12am | #2

   http://www.vanedwards.co.uk/glue.htm

   Search in page for glycerine.

1. 
   joinerswork | Aug 05, 2004 03:14pm | #3

   Uncle Dunc,

   Thanks, that's just what I was looking for.  I had just enough recollection to know what to ask for, and where to ask...sometimes that's enough to get by!

   Best regards,

   Ray

2. 
   joinerswork | Aug 13, 2004 02:01am | #13

   Well, I did it.  I ended up using the grade 135 hide glue (for extended set time) with just a splash (maybe 3-5%) of glycerine added.  I made up several mini-tambours, and laid them up with different combinations of glue, glycerine, and glue sizing or not, on the canvas.  Sized canvas, and small amt of glycerine gave the best results. 

   I made up a tray to support the slats, on a flat piece of 3/4" ply.  Clamped a straight edged pc of 1 by to the long edge of the ply, and butted the first slat to it.  Packed the rest of the slats against that, and squared them by clamping a rabbetted scrap to both ends.  Packed the slats tightly against one another and held them in place with blocks clamped to the plywood base.

   I coated one side of the canvas with thinned glue, and rolled it up.  Then started painting the slats with a fairly strong solution of the glue.  About every 6", I'd unroll more canvas, andf press it into place.  When I got to the end, I rubbed the whole thing over with my veneer hammer, but the canvas seemed to be stuiuck pretty well.  I added three re-inforcing strips (of the same canvas), one at each end, and one in the center, on top of the canvas,  mainly because the old canvas was done so.

   Today, I took the top off the plywood, and slid it into place.  Slid up and down nice and easy. And as ole blue eyes says, Nice and easy does it, every time! 

   Thanks to all for the information.

   Regards,

   Ray   

3. 
   jackplane | Aug 05, 2004 03:34pm | #5

   I rebuilt a tambour top desk once but used contact cement on the canvas with great results. May not sound kosher but it works. The trouble with hide glue is that it becomes brittle in short order- not the best adhesive in this application.

4. 
   OneofmanyBobs | Aug 06, 2004 02:10am | #6

   Glycerine keeps hide glue more flexible.  Too much and it gets like rubber.  Just a percent or less.  Before rubber was available, hide glue and about 10% glycerine or sugar was used to make rubbery rollers for printing presses.  I have some that are 80 or 100 years old.  Still pretty much like rubber.

1. 
   joinerswork | Aug 08, 2004 06:10am | #8

   Bob,

   Rubbery is just what I'd like, as long as I don't give up stickiness to get it.  I'll play with the proportions til I get it right.

   Regards,

   Ray

1. 
   OneofmanyBobs | Aug 08, 2004 06:37am | #9

   Hide glue is great for some things and not great for others.  Yes, it can be made more flexible and sort of rubbery, but it's not strong like that.  It tears easy.  Like a very tough jello.  To glue a roll-top, you don't put glue on the fabric.  Only on the slats.  Does not matter what kind of glue.  Lay them all out flat.  A very light coat with a roller on the slats.  Lay the fabric on top and push the fabric into the glue with a dry roller.  That way the joints don't get glued.

   If you're going to get glue all over the fabric, you need a decent flexible glue.  A permanently flexible PVA glue is a better choice.  Not Elmers or Titebond.  There are flexible varieties made for fabric and bookbinding.  Jade 403 is good.  Or, go to a fabric store.  They sell a variety of flexible PVA glues.

1. 
   joinerswork | Aug 09, 2004 04:32am | #10

   Bob,

   I've used jello (well, knox gelatin) before as a glue...so if it ends up as strong as that, I'll be satisfied!

   I appreciate your suggestions about how to apply the glue to the slats,etc.  That's pretty much how I've done in the past, on new work. I just don't want to have to go to the trouble to remove ALL the hide glue from the slats, to be able to use PVA.  Since the original glued fabric lasted maybe 60-75 yrs before the fabric (not the glue) gave way, I'll be satisfied with similar results.

   Actually, I'd thought about a light glue size on the fabric before glueing the slats, thinking it might improve adhesion, and not require such a heavy coat on the slats.  It'll take some playing around to get the best combination of additive and technique, I'm sure.

   Regards,

   Ray 

1. 
   OneofmanyBobs | Aug 09, 2004 05:44am | #11

   I do bookbinding as well as wood, so I'm real familiar with cloth and hide glue.  It would be a big pain to use hide glue for this since the area is so large.  You'd surely have to add urea to increase the gel time.  Also glycerine essentially keeps the hide glue partially hydrated.  Never really dries so it stays somewhat flexible.  Another undesirable side effect is that glycerine is a sugar.  Corn syrup or sugar or glycols will do similar things in hide glue.  But, bugs and rodents like it too.  A big problem with books.  You need to add camphor or formaldehyde as a preservative to avoid mold and pests.  Really a fair amount of effort.  PVA is good stuff considering all things.  Another option is hot-melt sheets.  I use fusible web all the time.  Iron it on the cloth, peel off the release, iron it on the wood.  Strong, flexible and tough. 

   The lifetime of the roll top depends as much on the fabric as on the glue.  Cotton will not last.  40 or 60 years maybe if its unbleached.  Not enough history with synthetics.  I wouldn't trust them not to get brittle or shrink.  If you want durability, unbleached linen is the stuff to use.  Sold as "airplane linen".  Unfortunately about $60 a yard.  Not too bad for a book, but you need a yard or better for a roll top.  Sizing the fabric is not a bad idea.  A couple light coats of spray starch works.  The glue will stick to it just fine.

2. 
   joinerswork | Aug 10, 2004 06:17am | #12

   Bob,

   Thanks for the good info.  I'll be playing with samples to try and get a workable combination.

   Regards,

   Ray

5. 
   joinerswork | Aug 08, 2004 06:08am | #7

   Metod, Jackplane,

   I've used yellow glue in the past (on new work) for tambours, too.  I guess the contact cement would work too.  I ironed the canvas onto the slats to set the glue quickly.

   This is an old desk, with an "S" top.  Since the old canvas was glued on with hide glue that is what I want to use too, mainly so I won't have to completely remove all traces of the stuff before re-gluing.  The old glue held perfectly well, but the canvas has deteriorated, resulting in separations at many of the tambour joints.  It seems to me that a "softer" hide glue will allow the tambours more leeway to flex both ways in going through the S turns.

   I've got some glycerine, and will experiment with adding greater or lesser amts before committting to the top.

   Thanks to all,

   Ray