Glue open time.

[garywayne]

Hello everyone.

When I eventually get round to gluing up my toolshelf/cabinet thingy, with the amount of dovetails involved it's going to take some time to piece together.

PVA glue doesn't have a very long open time. Is there another glue which I can use with a longer open time, or could I mix water with the PVA to extend the open time :?:

 

[George_N]

I think you will just weaken the glue if you dilute it, rather than extending the open time. You can usually assemble even quite complex pieces by pouting together groups of components and clamping as you go. A dry-run or two usually shows you the best order to do things in.

 

[Steve Maskery]

Gary
Don't water down your PVA, it will alter its properties.

If you want lots of open time, I suggest you use Extramite. Very strong, goes hard and gives you lots of time to work.

 

[Wanlock Dod]

Gary,

In similar situations I have used waterproof glue which seems to have a longer open (and drying) time than the non-waterproof equivalents (at least in the kind of glue I normally buy). Not sure if the differenc would be enough to buy you sufficient time though.

Cheers,

Dod

 

[dickm]

Gary
If you want lots of open time, I suggest you use Extramite. Very strong, goes hard and gives you lots of time to work.

I've always been a fan of Extramite (though I still think of it as Cascamite!) BUT, it now seems almost impossible to obtain. I was told that since Humbrol went out of business a month or so back, it won't be available at all in the near future.
Have bought the last tin from our local supplier and divided it into small, full containers in hope it will keep for a while at least.

 

[andys wood shed]

Gary
If you want lots of open time, I suggest you use Extramite. Very strong, goes hard and gives you lots of time to work.

I've always been a fan of Extramite (though I still think of it as Cascamite!) BUT, it now seems almost impossible to obtain. I was told that since Humbrol went out of business a month or so back, it won't be available at all in the near future.
Have bought the last tin from our local supplier and divided it into small, full containers in hope it will keep for a while at least.

Available here

http://www.screwfix.com/app/sfd/cat/cat ... 2&ts=47097

Andy

 

[whoops!]

http://freespace.virgin.net/melco/index.html

I've used Balcotan for some incredibly difficult pieces, and now I'm reluctant to use anything else. It really is that good.

The regular Balcotan has upto 70 mins open time, and when it cures it really is not going to shift. Depends how strong you want the drawer to be...

Good luck
Decklan (balcotan,balcotan, balcotan,...you know you want to...)

 

[engineer one]

ah glue open time the bane of all our lives. :? :twisted:

always try to break down the assembly into an order so you are clamping the bits in small stages, then when they are dry and firm make up bigger bits. does work, even if it sounds a pain.

definately do not water it down, unless you are using it as coating prior
to painting or plastering.

paul :wink:

 

[garywayne]

Thank you all for your replies.

I get the feeling that I shouldn't water down the PVA, and go shopping for some Cascamite, or Balcotan then.

Again, thanks for your response.

 

[woodbloke]

Gary - whist the old 'Cascamite' is very good, it does set glass hard and has a damaging affect on edge tools when cleaning up. In addition, there is no 'give', or slight flexibility, in the joint which makes it undesirable in certain situations where joints are flexed a little ie, chairs. This lack of 'give' means that the joint may crack at some point. Also, whatever is mixed and not used is wasted. It is for this reason that Alan Peters doesn't use the stuff. I agree with others that a carefully planned glue up in stages is a way to defeat short open times, but that can be difficult in the middle of summer when its a bit sticky in the 'shop. On 'tother hand if you are laminating something then 'Extramite' is the dogs whiskers.

 

[Colin C]

Gary - whist the old 'Cascamite' is very good, it does set glass hard and has a damaging affect on edge tools when cleaning up. In addition, there is no 'give', or slight flexibility, in the joint which makes it undesirable in certain situations where joints are flexed a little ie, chairs. This lack of 'give' means that the joint may crack at some point. Also, whatever is mixed and not used is wasted. It is for this reason that Alan Peters doesn't use the stuff. I agree with others that a carefully planned glue up in stages is a way to defeat short open times, but that can be difficult in the middle of summer when its a bit sticky in the 'shop. On 'tother hand if you are laminating something then 'Extramite' is the dogs whiskers.

I have to completely agree woodbloke on where you use 'Extramite' ( with is what Casacmite is now called ), it is no good for things like chair as I have seen lot of joints break down because of it.
For what you want to use it for should be ok but it can also go off very quickly when the weather is hot.
I would ( like it has been said ) plan how you are going to glue it up and you should be ok
Good luck

 

[Keith Smith]

Titebond 3 gives a decent open time and is what I use when I have a large project to glue up. The only thing to watch is it can leave a dark glue line.

HTH

Keith

 

[Steve Maskery]

Hey Keith!
Good to see you around, I thought you'd fallen off the edge of the world!

 

[Keith Smith]

Hey Keith!
Good to see you around, I thought you'd fallen off the edge of the world!

Hi Steve,

Not quite, it just feels that way.

Just too busy at the moment :roll:

I'll probably be desperate for work next year :lol:

 

[garywayne]

The reason for this question is because I lack in self confidence, and I tend to forget the sequence that I originally thought out.( I have a very bad memory, and my mind tends to wander). With the amount of glue area involved I am afraid that the glue at the start will go off before I finish applying it. I realise that the best way, (in my eyes), to put it together would be to glue the bottom first, making sure the sides are squire to the bottom. Allow to dry, then fit the top.

Nearly forgot. I also have very little space to work in/on. ie. The top of a workmate.

This is the bottom of the side panel:-

This is the top of the side panel:-

Before anyone says that there is an essayer way, or more simple joints, I have done this on purpose. This is to practice layout, measuring, cutting accurately, and glue up.

Thank you all for your input. I appreciate all responses.

I shall use PVA, but I shall also practice a few dry runs until I am confident.

 

[engineer one]

gary, we all forget, but i am sure your memory is not as bad as you would like to blame it.

don't forget that if you don't glue the top in you will have to spring the
sides to get it on, and that may cause you some problems.

i believe that once you have glued the sides and bottom, and placed them where you need, you will still have time to glue on the top, and then square it all up. norm does it, why should you not???? :twisted:

the other thing is by being more positive, it will be easier to ensure that the box is square, remember you need to ensure that the diagonals are the same length.

paul :wink:

 

[garywayne]

Paul. My doctor thinks my memory may have something to do with my medication. I have a court hearing next month, (very important), which I had forgotten, until my barrister phoned to remind me about our meeting.

Regarding the top. I thought that I would cut the top to size. Made to measure as it where. I take it that that would be the wrong way to go then :?:

 

[engineer one]

hi mate, sorry about the memory, know what you mean about forgetting meetings.

remember with the top, how the dovetails work, and by not assembling it all at once, you may well strain the bottom joints. take it one step at a time, don't worry and give your self the confidence to do it. :lol:

we are all rooting for you mate :wink:

 

[garywayne]

Hi Paul.

The way I have cut the dovetails the pins are at the top to prevent the sides from popping off. So I just have to pop the top on.

 

[engineer one]

ok, gary, just that i always thought you needed the wider bit on top, and not at the sides, to ensure that it did not pull out :?
always happy to have real experts tell me i am wrong :twisted:

paul :wink: