Cutting oak into thin slices - warpage?

[HammondR]

Hi folks,

I've just registered as I'm looking for some advice on dealing with solid Oak and I thought someone here may be able to help! Would appreciate any input.

I'm building bi-folding garage doors with a steel frame (for a variety of reasons, namely security). I want them to look like timber on the outside, though behind the timber is a strong box section steel frame with the gaps between the steel filled with ply. The outside will therefore just be a thin timber 'fascia' laid out as if it were a traditional timber door.

I was originally going to 'clad' the outside of the steel frame essentially with decking planks - cheap and weatherproof... But... I've decided it would be worth using something nicer. Decking planks are often bowed or cupped and don't look too good, knots etc.

I'm considering buying some big chunks of Oak - 2m long 150x150mm or so - and slicing them using my table saw into 10mm thick 'planks' which I will then use to recreate the look of a solid Oak door.

It seems that ordering the Oak in thin planks to begin with is prohibitively expensive, but buying thick chunks of it is a LOT cheaper.

My concern is whether or not my 10mm planks will cup/bow significantly when I cut them off? I would hate to buy several hundred £ of Oak and end up ruining it.

I have all the tools - router, table saw, can buy a planer/thicknesser if needs be - but I don't have much experience working with solid wood. I usually deal with ply, metal, etc.

Would appreciate any advice on this.

Thanks,
Rich

 

[RogerS]

Welcome to the forum, Rich.

I think you stand a high chance of the oak cupping, bowing and generally misbehaving either immediately after you have cut the wood (thus releasing the inbuilt stresses in the thicker timber) or after a short while after exposure to the elements. How about veneered ply suitably finished with something like Sikkens or Osmo?

 

[RobinBHM]

Id be tempted to look at solid 12mm oak flooring boards. Although these will be far too dry for external use and would need to be acclimatised outside under cover first and they may well cup. I suppose engineered flooring may be possible but I would be concerned that moisture would get through to the ply.

cutting slices from a large board will cause you lots of problems and if you mean oak 150 x 150 section you would need a large saw to cut through safely.

 

[Droogs]

Hi and welcome
have a looke at this thread for a bit more info. although the sizes are different the gist is still the same.

whats-going-on-t89148.html
Hope it helps

droogs

 

[Fat ferret]

You could get some western red cedar cladding and use that. Supposed to be very stable, I haven't used it before but nevertheless I would for your application. I would glue it on with poly urethane adhesive but not the t and g joins just the cedar to ply to allow for shrinkage.

I wouldn't bother trying with oak as it would probably move before you had a chance to stick it on.

 

[Sgian Dubh]

I'm considering buying some big chunks of Oak - 2m long 150x150mm or so - and slicing them using my table saw into 10mm thick 'planks' which I will then use to recreate the look of a solid Oak door. Rich

You might create more problems than you can handle if your experience is a bit limited. I would investigate some of the options already suggested by others, even though the upfront costs are at first higher.

150 mm square oak sleepers won't have been dried to the sort of moisture content you need, and at best only partially air dried. Even if they've been drying for two or three years, or longer, the core of the material is likely to be significantly above fibre saturation point (FSP), with FSP being roughly 30% moisture content (MC). All warping, splitting, surface checking and other drying faults occur in wood as it dries from FSP down to the sort of low MC needed for most woodworking jobs, e.g., for most furniture, joinery, carpentry, etc, although not all woodworking needs dry wood.

You generally need industrial quality sawing equipment to accurately resaw heavy and wet sleepers into thinner sections - I don't know if you have that kind of machinery. And you'd need to dry the wood prior to using it, and this requires a carefully stickered stack of your resawed boards to do the job, which you could do, either air dried or get someone to kiln it for you. But if this isn't done correctly, that's when all the warping and other drying faults I mentioned occur.

Ideally you want timber somewhere in the region of 18- 20% MC for your use, and this usually means buying wood that's already been dried close to this to make your cladding. This is where the 'high' cost comes in to the equation, because all the processing naturally costs time, equipment, space, etc. On the other hand, large sleeper sized pieces of oak, such as you're talking of, well suited for the right type of project, require relatively little processing to make them end user ready.

 

[HammondR]

Hi folks,

Wow, thanks for all the swift replies.

I'm glad I asked, it sounds like this might be a bad idea. I only thought of warpage as a bit of an after thought.

I think the oak I was going to order was already reasonably dry, but I would have to cut from each side to get through it with my table saw (in several passes, presumably).

Interesting comment about engineered oak flooring, I think the problem might be the lengths (are they just short lengths like laminate flooring? 1200mm or so?).

Failing oak then, my next best idea I think is to use redwood decking boards, but, I'm tempted to run them through a jointer & thicknesser to take the cup out of them.

I had thought about using ply with a nice top layer (eg oak) but I want to cut a few grooves and V's in the doors in certain places so the ply structure would get exposed, hence solid wood being the only real option.

I'm going to stain them quite a dark colour actually so hopefully they will come up okay. So long as it doesn't look like a set of garage door made from left over decking boards #-o

I'll post some pics when I get around to it!

Thanks,
Rich