Thread: wax to stop glue sticking?

I don't think you will get much springback if you use Techniglue epoxy to glue the laminations, although I must admit that I have not tried glueing nearly as tight a curve as yours. However, it is not going to work if you have to steam the wood. You may perhaps find, though, that the laminations are less liable to splinter once the epoxy is on them and has soaked in a bit. I think the job would be easier if you made a second former, so that the laminations are sqeezed between the two formers.

I still think the easiest way to stop your laminations sticking to the former is to line the former with brown packaging tape. I suspect that wax would just soak into MDF, so you would have to use a lot of it. It only takes a couple of minutes to stick the tape on, and the job is done.

Rocker

Hey Rocker,

Thanks for the advice, i have actually gotten some brown packing tape to try on the next glue up. It sounds far easier than anything else!

Your advice, if i need to steam the 1.5mm lams then it isn't going to work? - im not sure how thinner i could go... ill try get them to 1mm or under and see how i go. What is the downside of steaming lightly, the lams, to complete the bend? also, you suggest i might get the bend after coating in glue... i know this is a hard one to answer, but is the additional bend or flex you get once glues substantial? - ill give it a go either way.

I've also ordered a few glues to try out, one of them being Techniglue epoxy - hopefully arrives during the week so next weekend i can try it out!

Ill keep you posted!

thanks again
T

T , how about trying the bend with solid timber

Originally Posted by Manuka Jock

T , how about trying the bend with solid timber

MJ - funny enough, i haven't. It all started because lams where supposed to give me minimal spring back, and for consistency (2 individual legs) it was the best option.

I also decided not to go steam bent solid wood because i wasn't equipped for it. strangely enough, i think i've spent more time and money going the lam route, that i could have become 'equipped' for steam bending twice over.

is there good math i could use to understand the spring back in solid bent - so the legs are parallel? trial and error?

T

Originally Posted by ecks79

Hey Rocker,

What is the downside of steaming lightly, the lams, to complete the bend? also, you suggest i might get the bend after coating in glue... i know this is a hard one to answer, but is the additional bend or flex you get once glues substantial? T

Ecks,

The downside of steaming with epoxy is that water is not compatible with the glue. I can't really quantify how much extra bending you will get when the glue is on , but I think a minor amount of splintering will not matter too much, so long as it doesn't affect all the laminations. Possibly, if steaming is essential to achieve the bend, it might be better to go with a poly glue, which is compatible with moisture; but I have never used poly glue for bent laminations myself, and I am not sure if its working time would be adequate.

Rocker

Originally Posted by ecks79

MJ

is there good math i could use to understand the spring back in solid bent - so the legs are parallel? trial and error?

T

Not that I know of . have a look around the net .
The timber used will probably be a factor

Thanks Rocker.

I don't actually glue up while the wood is still damp, i steam to get the bend once, then leave the clamped lams till they dry... steaming and bending once gives it enough flex that i can come back a week later and bend the lams a second time without stressing or splintering. So in this case, moisture shouldn't be a problem?

I was more concerned that, since i require so much steam and force to get the lams around the form... that the glue was not holding that shape over the week after the clamps had dried, and therefore flexing out of shape.

If the lams are dry, and having been bent once, allow me to bend again when ready for glue up - would this pose the problem i just mentioned?

Originally Posted by Manuka Jock

Not that I know of . have a look around the net .
The timber used will probably be a factor

Thanks MJ.

I have been looking all week, the general consensus seems to be "there is no definite way" and i've been advised that lams are really the only safe way when looking for conformity.

Ill find away )

Cheers
T

I think once you get the lams bent and dried close to the correct bend you'll find that gluing them with the Techniglue will give very little springback. It's a very hard epoxy with virtually zero creep and for the bend to spring to any degree, the glue must creep.
You may also try overbending the lams and drying on a tighter form and hot pipe bending would certainly be worth investigating to do these lam bends. I have hot pipe bent 3mm lams to a 13mm radius so your radius is doable.

Cheers
Michael

Hey thanks Michael... appreciate the feedback. Ill give that a go, sounds like it will be my best bet, as well the Techniglue sounds like a much better glue to work with

Cheers
T