- 12 November 2017 at 12:16 pm #364101Dave CParticipant
I finally got the confidence to try out a more challenging project (for me at least!), making a small side table (with mortise and tenons).
For the first time, I got the oak for the project milled/squared by the lumber yard. They said it was kiln dried, and that they mill it carefully on all 4 sides to minimise wood movement, so said it should barely move at all.
I got the wood home and left it for a week, it didn’t move at all, so I laid out and marked all the mortises and tenons.
I ended up having to work or was away for 3 weekends after that, so had time to chop the mortises, but not cut the tenons.
Looking at the wood now though, the tenon pieces have cupped a bit (if I lay a straight edge on top of them, there’s a 1mm gap on each side).
I’m not sure what to do now – can I just try to cut/fit the tenons as they are now? Is the wood movement small enough to allow that?
Or do I need to start from scratch – square the wood again, taking off enough to remove all the existing tenon layout marks, then mark new tenons? I’m worried if I do this then my tenon pieces will all be undersized by a fair bit, since I’d already gotten them to the final size I wanted.
Also, was there anything I should have done differently from the start? Should I always assume that even kiln dried and milled wood from a lumber yard will still move a lot, and that I should leave for longer to acclimatise at home? Or should I just have marked/cut my tenons much sooner after getting the wood home?
I’m a bit disheartened at the moment – the oak wasn’t cheap and I don’t usually have much spare time, so dreading having to start again…
You must be logged in to access attached files.12 November 2017 at 9:36 pm #364682ZepposParticipant
Have you left the tenon pieces lying with one side on a flat surface? Then the moisture contents can change differently on the open air and closed from air sides, resulting in cupping. Just leave them such that air can circulate on al sides and you may be good. When leaving prepared wood wrap them in cling wrap is a method folks use to avoid movement (but now do that only once the wood has ‘uncupped’ again). Hope that helps.26 January 2018 at 12:37 am #451089bigaxeParticipant
My very first woodworking project was using kiln red oak and I had the same problems you described. I never used kiln dry oak again.
I would plane the tenons flat and then glue on a thin piece of wood to get the required thickness26 January 2018 at 11:39 am #451509btyremanParticipant
this is why speed is important in joinery, I try and do all the joinery on a project in a single day so that to minimise risk of movement, it’s normal with oak for movement to happen, you really have to be careful how you store the wood, never leave it overnight on a workbench top, air needs to flow all around the wood evenly. I’ve had pine move a lot as well, not just oak, but since learning about stacking wood, it’s not really been a problem.
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