adhesive info and advice pls

[Tim W]

When I learned woodwork there only was a choice of two glues. Now I need some info about alternatives. This is what I am doing:

Involved in the restoration of a very old building I am repairing oak window frames. A long job of scarfing and letting in new pieces of oak and jointing in new sills. I was using pva but the recent low temperatures have given me a lot of grief. The night time temperatures in the barn/workshop are around freezing and the glue doesn't work.

I don't like the idea of Cascamite (urea formaldehyde?) because I need a lot of small quantities of glue through the day, so I don't want to mix up a batch with a short life. Also I was keen to have a little movement in the glue between the old and new timber. I have never used polyurethane or epoxy or animal glue or electric glue curing devices and there are probably other options I have never heard of.

Seeking knowledgable advice or web pages/pdfs. Low temps, small quantities, weather resistace, old to new. Clamping times are not an issue, brute strength is not an issue, joints can be made reasonably close but they are hand cut and often saw cuts to be glued so there is gap-bridging and crack filling to consider.

Tim W

[Tyke]

Sounds like a good application for 2 part epoxy. There are many varieties on the market. The main difference is working time and whether the mix has to be exact. I get "non-critical" 1:1 mixes which means theye ideally want

1 part of resin to 1 part of hardener, but if you mix differently it will still cure but may take more, or less time.

It is easy to find 5 min vs 20 vs 60 minute working time.

Lee Valley has a decent selection of glues.

Paine.

[dadiOH]

No real recommendation here, just mind doodlings...

My favorite general purpose glue is TiteBond ll. Water resistant, reasonable flexibility but doubt it would be good in low temp (fine after setting). TiteBond 3 is totally waterproof, same reservation. Both need reasonably good joints, wood to wood.

For gap bridging, epoxy with the addition of Cabosil as a thickener is wonderful. Very strong, no clamping needed, waterproof. However, useable pot life is short - if you don't like Cascamite's you would hate epoxy's. It also requires warmth (60+) to cure - that could be fixed with a space heater? You mitigate the pot life by cutting a bunch of joints, mixing some epoxy and gluing a bunch at one time. Good source...

lieu of epoxy you might be able to use polyester or vinylester. Pot life is very short (variable depending on how much catalyst is used) but that could be an advantage since you could use a hot mix and not have to worry about low temps...unlike epoxy which gradually sets up over several hours, they set up very rapidly once they start. Same source as the epoxy.

There is also polyurethane glue. Needs moisture to cure so the low temps might kill it for you. It is good at bridging and is strong but I personally dislike the stuff - it foams.

-- dadiOH ____________________________

dadiOH's dandies v3.06... ...a help file of info about MP3s, recording from LP/cassette and tips & tricks on this and that. Get it at

[CW]

Epoxy cures by chemical reaction. That reaction is slowed by low temperatures. How long do you want to wait?

[dadiOH]

A mastic might work for you. I'm thinking of Liquid nails or similar...even an acrylic caulk. Much would depend on how important appearance is to you (paint/no paint) and how much strength you need.

Something like that would at least solve the gap filling/low temp problems.

-- dadiOH ____________________________

dadiOH's dandies v3.06... ...a help file of info about MP3s, recording from LP/cassette and tips & tricks on this and that. Get it at

[Tim W]

Hm, the oak is to be painted, but I am concerned about permanence and adhesion. these windows are 300 yrs old (which is why they are repaired and not replaced) and when they go back in the house I want them to be good for another 200yrs at least of winter/summer night/day sun/frost. I know you say you don't like the polyurethanes but my reading suggests they may work well. Especially their strength in end grain joints. A lot of these windows I have to cut off the rotted lower end of the stiles and scarf in a new piece. Why is the foaming a problem?

Tim W

[Tim W]

I don't mind cramping and leaving for 24hrs, although just overnight would be better. The problem I have with the PVA is instead of drying clear and hard it is drying at low temperature to a white chalky paste which sticks not at all. It would be alright if it was just a bit slow.

Tim W

[dadiOH]

Nuisance, messy....

Some urethane info...

[Steve knight]

most glues don't work well below 50 degrees. a faster cure epoxy would be one way to go. or make a tent of plastic with some light bulbs in it. that should work. anything below 50 and yellow glues get pretty weak. if the wood is cold the glue does not spread well and you need more clamping force too. otherwise the clamps can fall off and you know the joints are not tight. one way aroudn this is to clamps up then in 5 minutes check the clamp pressure.