GRW

[GRW]

Hi,
I have a problem when using the metal hinges on turned boxes. After a period of time they sometimes come off. I use Araldite, the glue doesn't seem to bond very good to the metal. If the hinge is stiff or the catch tight. Any suggestion to help would be welcome.


Thx
Gordon

[Chief Tiff]

I can think of three possible reasons here:

1. Is the wood moving? Wood contracts and expands with humidity, it might be moving enough to shear the glue line.

2. Incorrect surface prep: the metal needs to be keyed with coarse-ish emery paper but the wood should have a smooth tooled finish, not sanded.

3. Wood compatibility: an oily wood will give a weak joint unless you can remove it. Liberally wipe down the glue area with acetone immediately prior to spreading on the glue.

In your next post if you can give a few more details like wood type and glue brand you'll probably get more informed suggestions than I can give right now.

[GRW]

Thanks for your reply, The Glue was 5 Minute Araldite and the timber used was Myrtle, The cleaning and using acetone might help. I guess I am trying to glue 2 completely different materials,

Thanks Gordon

[Chief Tiff]

Perhaps try a polyurethane glue? Same prep required but you have to really securely clamp the pieces together. As the glue cures it foams up and forcibly penetrates into the timber plus it sticks well to just about any metal. Finally it remains slightly flexible so wood movement shouldn't affect it as much as epoxy. The only downside I can think of is removing the excess glue that squeezes itself out as it cures. I've tried masking off areas but it will force itself under tapes! I just use the minimum I think I can get away with and frequently remove squeeze out with a rag dipped in acetone, or simply wait till the next day and carve it off with a chisel.

[GRW]

Hi Chief Tiff, thx again, Would a glue like Titebond probably be better, it would be easier to clean up,


Thanks Gordon

[Chief Tiff]

I would say no PVA or aliphatic glue will be any good;they don't bond real good to non-porous stuff like metal hinges so that rules out all the Titebonds and Selleys glues except for their polyurethane products. Sika do a good one too and all 3 brands are available in small bottles.

Perhaps you might just need to change your epoxy glue? The rapid setting ones lose a bit in flexibility and strength; maybe change to a normal or marine grade?

[GRW]

Thanks for your help I will try that and clean the metal better,

THX, Gordon

[Allan at Wallan]

Thanks for your help I will try that and clean the metal better,

THX, Gordon


Might be a good idea not to let me handle it Gordon as I
was the one who did the damage (the second time).

Allan