The Society of American Period Furniture Makers

Tools and Techniques => Veneer and veneering techniques => Topic started by: macchips4 on December 19, 2012, 08:17:22 AM

Title: working temperature of hide glue
Post by: macchips4 on December 19, 2012, 08:17:22 AM
     I have some repairs on veneers of an english tall clock that need regluing and some patches. The only location to work on this thing (over 8 feet tall) is in an unheated garage shop, Its about 40 degrees here in NY, warms up to about 50 during the day, and I'm sure willl be getting colder soon. much "cold" does hot hide glue tolerate?
If the "drying" is by cooling and evaporation I would think that as long as it is not near freezing the glue should be fine just the open time would be drastically reduced. I'm sure centuries past wood was glued in cold/winter conditions. Does anyone have any experiance with this situation?
Title: Re: working temperature of hide glue
Post by: HSteier on December 19, 2012, 09:01:04 AM
Think of hot hide glue as "Jello plus". As hot hide glue cools it gels first and then hardens. You have to get your work lined up and clamped or hammered before it gels. Gelling depends on temperature. The cooler it is the faster it gels. It's very difficult to work with hot hide glue in cool temperatures.
Sometime veneer can be repaired with cold hide glue. If you can get a syringe and inject the glue into any cracks in the veneer and then clamp it down you will get an excellent repair. For completely loose pieces the hot glue works better.

Howard Steier
Title: Re: working temperature of hide glue
Post by: FrederickH on December 19, 2012, 09:16:50 AM
Can someone here tell me how the squeeze out from the hide glue is cleaned up after the cauls, for the work on the veener, are removed?
Title: Re: working temperature of hide glue
Post by: R Bohn on December 19, 2012, 10:23:55 AM
   I often work on sites that are not ideal for the task. But when cool temps are involved, I tend to stiffen up before the glue dries. I try to find a place that is the same temp as where it is to be displayed.Maybe you can find a hallway, corner of a room, or someplace to lay the clock across a couple sawhorses to do the work. If you are repairing a few chips, your garage will work, but if major lifting and re gluing is needed, cold will make for a tough job. If that's all you have, and I've been there, use a couple flood lights or heat lamp to keep thing flowing.  I once repaired a dinning room table in the women's rest room at the Henry Ford museum because of a lighting problem. What ever works!
   As for squeeze out, If your repairing, and the veneer has finish on it, I like to use 3/4 in masking tape to cover the joints. stretch the tape a little to pull the pieces together. The dried hide glue will stick to the tape and not the finish. If your working with unfinished veneer, try to spread the glue evenly with a straight edge making sure to coat corners and thin heavy glue spots. Tape a joint and work to an edge of the veneer where you can remove most of the excess glue. A roller or hammer works well. then tape where needed to hold the veneer down. then clamp. I keep a damp rag handy to keep things in check as I'm taping.
  After removing the clamps, use a damp rag to scrub any problem spots.  Good luck    Randy
Title: Re: working temperature of hide glue
Post by: R Bohn on December 19, 2012, 10:35:40 AM
   A handy tip if your re gluing large areas or things like broken banding or a lot of small pieces.  Place a piece of tape along a straight seam , and place tape over the entire area to be lifted. Then you can use a putty knife or knife to lift a large area and not worry about small chips getting away from you. Use the tape as a hinge and alignment won't be a problem ether.  Do Good Work    Randy
Title: Re: working temperature of hide glue
Post by: Adam Cherubini on December 19, 2012, 09:56:02 PM
I think the problem you will encounter is that the glue will jell and you won't be able to reduce the bondline thickness during clamping.  If you must work in a cold area, you will have to warm the mating surfaces immediately prior to gluing.  A hair dryer might work.

If it was a gappy joint, you MIGHT be able to get away with it.  At least, I would mix the glue pretty runny (but that won't stop it from insta jelling- only help control the bond thickness).

Hey Yanks- just a shout out- England stays fairly warm and fairly humid year round. Yes there are cold wintery days.  But by February it gets back to 50 in the sunshine.  Most craft shops probably had a fire place or stove, which, since it also never gets too terribly hot (cept for maybe 2 weeks a year) you can have lit just about everyday.  Modern Brits living in the country still warm their kitchens at least with Aga's, cast iron, often oil or gas burning stoves that stay lit and hot all 24-7-365.  Their climate is very different from ours and lots of traditional joinery, materials works better there than here.
Title: Re: working temperature of hide glue
Post by: Freddy Roman on December 19, 2012, 10:25:32 PM
I would say use heated cauls, or Old Brown Glue.  For Old Brown Glue from Patrick Edwards gives you great open time, and all is necessary is a warm bath of water to help thin the glue.  I would say 40 degrees is just too cold. Or Tape on some heat warmers on the patches to be glued. 

Title: Re: working temperature of hide glue
Post by: Jack Plane on December 20, 2012, 01:33:24 AM
When I was a restorer in England, I used to go through the scrap bin at the local steel yard for off-cuts of 3/8" thick flat steel bar of various widths. I kept them on a rack on top of the workshop stove during the winter and placed them on any glue surfaces for a few minutes before applying the glue. The hot steel would leave the wood hand hot which was more than adequate for the average glue-up.
Title: Re: working temperature of hide glue
Post by: ttalma on December 20, 2012, 09:35:58 AM
Not sure if this would work or not but could you place a heating pad or electric blanket over the work to warm the substrate. I think an hour or so of that would warm the substrate throughout.

I can also suggest the 500 watt lamp they trough off enough heat to keep you working area warmish.
Title: Re: working temperature of hide glue
Post by: macchips4 on December 22, 2012, 09:58:38 PM
Thanks to all for reponding. I starred at this clock case for a while, sat and pondered, and decided two things:
      1) I should have charged much more (like always, someday I'll get it right) and
      2) I't will take too long and make the repairs more complicated in an unheated space. The garage won't do.
Soooooo... I "re-arranged" some things in the side-yard of the house (plants etc), "adjusted" some bricks around the basement windowwell and brought the case into the basement through the window.  Now to figure were to start on the veneer repairs! It looks like quite a few people have worked on this before and will need to undo some of the hack work and titebond glue, replace some braces and start regluing the structure before any cosmetic work can begin.
Title: Re: working temperature of hide glue
Post by: Jeff L Headley on December 22, 2012, 10:09:00 PM
Veneer repair of an English clock! Thin oak covered with Mahogany? With a 40 degree substrate  Warm sand bags 90 to 110 degrees for seven minutes laid over the gluing surface. Then glue and clamp. Your main problem will be your veneer thickness. Do you have a big area to patch?
Title: Re: working temperature of hide glue
Post by: macchips4 on December 23, 2012, 01:44:50 AM
     Yes looks to be mainly oak carcass with mahogany veneers, burl panels and stringing  outlineing the panels, mouldings etc. There have been many , many additions to the carcas, the burl panel were backed up with what looks like old pine????? there are battens everywhere and the back has been replaced and screwed to new "chines". the burl base panel is split from shrinkage but are not repaireable because of the backing that was glued on, making the original 1/2 thick panel about 1 inch thick, now must be infilled to hide (i'll try) the split. elsewhere the veneer repairs are missing edge banding, stringing and multiple veneer patches(about 1-2 sq inches each). I need to make neww hinge plates, patch area for hinge pins, and replace missing finials, I managed to get the waist door open (no key, door locked shut) by reaching in and unscrewing the lock. I will open the lock and file a key blank to match lock then reassemble. I have not decided to polish entire case or just repair areas to match. I'm already behind the eight ball on this. I have old mahogany boards to slice for the verneer patches and I did some experimenting with cherry and dye to match the stringing. What I'm uncertain what to do is the door frame.... the veneer is split very 1 1/2 or so all around the door and slight lifting at each split..Just hope the hot hide glue can resoften the glue under the veneer at the splits and allow me to clamp the area flat. The process is --A little work ,let dry, a little work, let dry....then repeat.