Problems

[Colin]

Hi all,I’ve just started turning mostly goblets etc.been doing a lot of glueing different  woods.so turning,sanding and waxing all on same day and they feel very smooth,but after bringing them in to a warmer environment after a few days you can feel the ridges between the two different woods.it doesn’t seem to be the glue giving way.so I’m having to put them back on the lathe and sand and polish again,I’m using gorilla glue,any ideas where I’m going wrong please colin.

[Les Symonds]

Hi Colin, and welcome to the forum.
It all comes down to moisture content and moisture variation. All timber absorbs and loses moisture to adapt to changes in environment and bringing timber from the workshop to the house will result in movement. In a normal bowl or goblet, that wouldn't be much of a problem, but with segmented work you have timbers of varying densities, glued together. The less dense, open grained timbers will lose moisture much quicker than dense, close grained timbers, so the timbers are shrinking, by tiny amounts, but at different rates to reflect the change of moisture content, thus the little ridges at the glue joints. You can minimise it by bringing the timber segments into the house for a few weeks before the glue-up, or by having a warm cupboard (heated by a light bulb?) in the workshop.

Hope this helps a little...Les

[Colin]

Thanks very much les,some very useful info,think I’m going to use cupboard and light bulb as you suggested

[Colin]

Just a thought les,would the light bulb idea work for new logs as I’ve waxed the ends of some and been told they have to be left for a year,I did turn some when I started but they split very badly.thanksfor your prompt reply earlier colin

[Les Symonds]

Hi again Colin...no, it wouldn't work for logs...this works only for seasoned timber. In centuries by-gone, the rule of thumb among trades such as wheelwrights was to allow one year for each inch of thickness of a timber for it to dry, and then to add another year for good measure. Large baulks of timber need to dry slowly to reduce the unwanted effects of drying too quickly. In a nutshell...there ain't no shortcuts to seasoning, especially not in segmented work.
You've certainly done the right thing by waxing the log-ends.....you've simply got two choices now. firstly, you learn to be patient, secondly, you learn the dark art of working green wood. Many of us choose a path somewhere between the two, impatiently working a few green pieces for the sheer fun and satisfaction of working green wood, but also salting a few logs away and forgetting about them for a few years.

Les

[bodrighywood]

I do a lot of goblets and many from different woods, as Les said you need to use dry woods to make composite pieces. The difference can even break the joint at times. Drying the wood first, Les's methods or simply being patient is the only answer I am afraid.

Pete

[Colin]

Thanks les and pete

[Derek]

Maybe some one can correct me if I am wrong but someone suggested to me that once the wood has settled that cascamite is better for gluing segmented work as it does not creep like the PVA types. Can't you tell I don't do segmented work well not yet anyways

[malcy]

I do a lot of segmented work and I use a 5 minute set PVA adhesive all the time. Segmented pieces can show ridges at the joints after turning and finishing but not immediately after finishing. The ridges appear after a day or two even in the same atmosphere as when first made. The problem is thought to be that the adhesive dries from the outside in and even if the adhesive appears to be dry when the part is turned you are exposing a fresh surface which may not have dried so much. This moisture still in the adhesive causes the wood in proximity to swell slightly and form the ridges. If the piece is put back onto the lathe and lightly sanded to remove the ridges and then finished, you should not see the problem again. Not used any other adhesive for segmented work so not sure if this is true for your adhesive. Hope this helps. Malcolm

[Colin]

Thanks Malcolm,perhaps I’ll try a different glue,but I’m sorting out a cupboard and light bulb as les suggested,but all been very helpful

[Colin]

Thanks derek