Which External Glue

[John15]

I am currently making 2No. 6' x 3' side gates for my house as mentioned in a previous thread.
The frames are in Oak with M and T joints but I'm undecided which glue to use. Previously for external use I've used Titebond 3 but wondering if Cascamite would be better.
Any advice would be greatly appreciated.

John

 

[custard]

If you're a full time woodworker in a jigged-up professional workshop then Titebond is a great adhesive. You've made the same thing many times before so you know exactly how long assembly takes, and if anything goes awry there's loads of spare cramps and other woodworkers to quickly give you a hand.

But for the hobbyist the long open time and "grab free" nature of Cascamite has a lot to offer. If you're assembling a few M&T joints it will give you time to carefully check for square, and if one of the M&T's is a tight fit Cascamite won't suddenly "grab" before the tenon is fully home. Plus, if something goes seriously wrong you always have the option of knocking the whole assembly apart, cleaning out the joints with hot water and sorting out the problem in a leisurely fashion before trying again tomorrow.

I've heard some hobbyists moan that Cascamite is a faff to mix up. That's true, but craftsmanship often requires effort!

Good luck.

 

[Myfordman]

I've had excellent results using PU glues for external woodwork but you must clamp the joints as the foaming action can open a joint during the cure.

 

[Beau]

PU is ideal for this sort of application. I like this one http://www.robbins.co.uk/Pdf%20Files/Co ... mparoc.pdf

Sure Cascamite would be fine though.

 

[Phil Pascoe]

Be careful, though - some PU's don't leave you much open time.

 

[memzey]

I've had no problems with titebond 3. It works great in my experience as long as you prepare for final glue up with a proper dry fit (which I think it's always good to do regardless of the glue you are using).

 

[cerdeira]

epoxy.
loads of open time (up to 60 min, depending on the type) and suitable for exterior applications.
only drawbacks are price and it can also leave a slightly darker glueline.

 

[Beau]

Be careful, though - some PU's don't leave you much open time.

Agreed with some types but this is ideal. Long open time but quickish drying time http://marinestore.co.uk/Collano_Sempar ... ment_.html

 

[John15]

Many thanks everyone for the advice. I think I'll give Cascsmite a go. I'll let you know how I get on.

John

 

[marcros]

if you do, decant the powder into small airtight containers. Then as you use it, you are not exposing the whole lot to the atmosphere which may(will) shorten the shelf life substantially.

 

[Ed Bray]

I used cascamite for the first time this week and have been surprised how easy it was to make up and use. I followed the instructions on the container and made it up, 2:1 with half of the water first and then mixed all the powder in before mixing in the remainder of the water.

I was joining 8x 66" x 7/8" planks with 5 dominos in each joint, took my time making them into four sub assemblies, then into two assemblies and then the following day (last night) joined them into the final board.

I have had the cascamite for some time but never got around to using it before. I will definetely be using it again in the future. Downside is, It does seem to leave black stains if you get it on your skin though.

 

[Phil Pascoe]

There is a hardener for urea adhesives - K10 - which I believe is phosphoric acid - which you can put on one side if you wish to speed the process up. This gives a long open time and a quick set when assembled - ideal for complicated assemblies, you can do a bit , leave it a while come back and carry on. :idea:

 

[RobinBHM]

PU glue is available in different open times.

http://www.thegluepeople.co.uk/index.ph ... ducts_id=7

I know the link does not show it, but this is available in rapid and standard. The standard gives plenty of open time for assembly. Whilst pu glues are probably the strongest, the foaming agent makes them messy. Cascamite is easy to clean up with a wet rag.

 

[John15]

Many thanks again guys - looks like Cascamite is the popular choice.

John

 

[pcb1962]

How long will mixed up cascamite keep in an airtight bottle?

 

[Phil Pascoe]

All of the PUs I've seen have been 5 mins or 30 mins. Even 30mins. doesn't allow you very long on a complicated cramp up in warm weather, especially if you are damping the joints. (Which makes the glue expand better). There are undoubtedly glues that have longer open time though.

 

[AndyT]

How long will mixed up cascamite keep in an airtight bottle?

It won't. Mix up a little more than you need in a yoghurt pot and throw away any you don't use in that session. Try to keep the rest of the powder dry. If it takes in moisture from the air it will set solid before you want to use it next time.

 

[James-1986]

The best exterior adhesive available is phenol resorcinol, sold as poly proof, cascaphen etc. Far superior to anything else, the only downside is the dark glue line. It also has a decent open time. I don't understand why all these manufacturers think joiners want glue with such short open times. I'm sure titebond 3 is as good as they say it is, but how am I supposed to assemble a door properly in 5 minutes? Glue one joint at a time?

The best UF glue I have used is 'one shot' made by sovereign chemicals. I should think this will be good enough if your joints are well made and the tenons are wedged.

 

[Phil Pascoe]

The other downside being the price? It's not good for gap filling either. I used Everbuild UF for my bench as I only had one clamp and all the m&ts were draw bored. It was perfectly good.

 

[James-1986]

£20 on top of the price for a big pair of oak gates is not worth mentioning. Also consider that if the job lasts longer then you're saving money in the long run.

A work bench is not going to be out in the weather and baked by the sun, any old glue is perfectly good for a bench.