Glue Open Time and Closed Time questions

[wollybugger]

Can I get a little explanation from you folks as the web get contradicting:

1 - That's the maximum time from when I slap it on to when the boards are joined? So if its label 10 minutes open time, and I put it together in 2 seconds, I'm OK? (This is where other web articles would like you to wait until it gels a little.

2 - The Cascophen I bought has 0 min open time at 90F... does that mean it can't be used at 90F? (Although the instructions give you working like and closed times at 90F)

Also, if someone can explain a little what is physically happening to the glue to define these times, I would be interested ... not microchemically ... but generally

Thanks as always!
Robb

[Jim Ledger]

The glue skins over, so when the pieces are brought into contact there's a barrier between the liquid glue, which may or may not dissolve.

There are probably chemists here who could do a better job of explaining, but I probably have more clamps than they do.

[wollybugger]

... but I probably have more clamps than they do.

Haha ... thanks

[Bob Smalser]

As Jim said, "open time" is how long you have to spread the glue and allow it to soak in before assembling and clamping.

"Closed time" is how long it has to be left in the clamps.

And while I've never used Cascophen, I've used plenty of UF Resin glue of one make or the other without problems of it skinning over too early because of heat. UF Resin glues are noted for longer open times than aliphatics like PVA's, and resorcinols for longer open times still. I suggest you try it in the shade in hot weather and see.

[MiddleAgesMan]

The only adhesive I know of that requires some time to "set" before joining the parts is contact adhesive. There may be others but in general you can apply glue and put the parts together without delay.

[JoshuaIII]

Using Cascophen often, it does need to sit clamped really lightly(Dare I say barely touching to not skin) on dense wood like White oak and the like for a certain amount of time before tightening the assembly (Look into the manual).

Cascophen for those who don't know is a resorcinol type made by Hexion as DAP do not supply it anymore.

[wollybugger]

Thanks for the advise all. I tried it out yesterday. Definitely has a lower viscosity than Aerodux 185 (which is good and bad) and needs to have 70F as min Temp ... which was OK as ambient was a little under 70F and I boosted the garage temp a little with kerosene heat. (Aerodux is >50F).

But the slightly higher viscocity give Aerodux a little more gap filling (I suppose).

So my verdict, from a new guy point of view, is I like the Aerodux better, but only by a small margin.

Thanks again for the advise

[JoshuaIII]

Cascophen is not gap filling, so I do not see that as a advantage or not...
(The 185 it is lightly but not recommended either)

Use a electric heating blanket for your lamination, it's a lot cheaper then heating the whole shop ;)