advice and help please New too all this

[farmerjohn]

If you think you may have to resaw your oak it would be worth going a little thicker like 2 1/4 inch. If you mill at 2" by the the time its shrunk when drying your going to have less to play with. If it were me I would mill to the size I wanted initially. Of course allowing for a little(10%) shrinkage.

I've wasted a lot of time this week resawing beams. I would always mill small butts through and through. Any other configuration would leave too narrow boards.

James

 

cheers for that james,

can i ask what you would consider the smallest diameter but that is worth quarter sawing? and i take it anything below that you would cut through and through.

Thanks, John

[agg221]

I agree with James on not looking to re-saw. It just adds to the drying time. I have squeezed 25mm finished planed all round size out of 32mm milled, but it was very tight. This gives an idea of the 'extra' to leave on when milling.

 

Minimum size for quartering is probably around 2'6" mid-quarter diameter, although if there is a serious taper I would look at the top end instead and say minimum 2'. However, I might not quarter something slightly bigger than that if it was short and I was making 3" slabs or similar. Anything much over 3' would end up quartered as a matter of course as there is not much use for boards that wide so they will be ripped down at some point anyway and it might as well be sooner and make the milling easier.

 

Alec

[farmerjohn]

WOW, i didnt realise that you lost so much,

some rough sawn dried oak i got was 26mm thick before i started planing and prob took off 3mm top and bottom and it was pretty straight, what size do you think that was milled at?

also, it was pretty good, not a lot of twist or cupping (hence only 3mm each side) is this normal on a 5" wide board or was it pretty well dried so not to need as much taking off?

Alec, your 3" timber, do you kiln that? if so how long do you air dry it for before kilning? or what is a minimum time is the more appropriate question?

What thickness would you expect 3" milled to shrink to and then plain up to?

Apologies for all the questions guys i really do appreciate all the advice.

[farmerjohn]

Alex,

was it yourself i was talking on here and we got off topic talking to about insulation materials, specifically for me a lime insulation render we had started to use?

[muttley9050]

The loss is in the shrinkage not the planeing. I probably plane around 1.5mm a side. Allow for 15% loss from mill to par.this will allow for a small amount of cupping. I've never had a problem drying oak. It can kick on big knots, just follow the rules. Oak should be air dried 6 months an inch up to about 3" before kilning. Thicker I would leave longer. Some Other species can go straight in kiln.

[agg221]

Thickness to be taken off when planing varies depending on width and sawing pattern. Quartering takes the least as the boards don't cup, through and through can cup more, so the wider the board, the worse it is. I would say taking 3mm off each side of a 5" board suggests significant cupping, twist or irregular grain.

 

% loss from mill to par depends a bit on thickness - shrinkage is a %, planing is more of an absolute, so 25mm par from through and through sawn 150mm widths needed 32mm starting (20% loss) whilst 3" (75mm) quartered would probably only shrink to 71mm and could be planed at around 68mm (10% loss), but if through and through sawn and significantly cupped on a wide board this could be finished size of 60mm to get it par.

 

The thicker sections are for outdoor use (boat bottom boards, or furniture) so I wouldn't kiln even if I had one. In practice, I air dry everything anyway. I then let it stabilise indoors for a bit before use, if the plan is for it to come in.

 

Yes, it was me you were discussing insulating lime render with - ultimately I plan to use it on the exterior of my whole house once the cement render eventually gets stripped.

 

Alec