Help with working out how much unplaned wood I need...

[Weirwolf]

I've been looking at Ross.K's wood thread with great interest and I'm interested in some of his sycamore to make a new bed.
The trouble I have is I have a cutting list for planed timber and his timber is obviously un-planed.

I recon I need just short of 9 cubic foot of wood in various lengths.

How much do I allow for in planing? :roll:
And do I have to allow for wasteage as well?
Does it work on a percentage or does it depend on my cutting list? :-k

 

[big soft moose]

between 25 and 40% for wastage is normal (which includes the wastage in conversion from sawn to PAR) - therefore if you want 9 cu ft of PAR you need between 12 and 15 cu ft of sawn (exact percentages depend on the state of the wood, dryness, etc)

 

[Weirwolf]

BSM, thanks for you reply.

I'm working from some plans I have found and so some wastage has been factored in already. For instance my plan calls for 1 1/16" timber, but the thinnest Ross quotes is 1 1/4" (30mm).

Having said all that, I think I'll plump for the 15 cu ft just to be sure.

I'm one to over engineer things and so I was going to up-thickness everything anyway. That and its not as if any wood left over would go to waste. :lol:

 

[Ironballs]

Thickness is a tricky one as it depends very much on the state of the timber you're selecting, eg I planed up some sycamore from Boddy's the other day that was not far off PAR, I needed a final thickness of 22mm and was okay starting at 25mm; but I've had other boards that are all over the place and had to take quite a bit off.

Generally speaking I'll allow 6mm on length and width to give sawn dimensions when doing a cutting list, allow about 5mm on thickness but hold judgment until I can see the boards

 

[OPJ]

If these are waney-edged boards then you should really be looking at what's known as 100% wastage! :shock: It may sound confusing but what it actually means is that you're aiming to buy double the quantity you actually require. :wink: This is to take in to account things like sapwood, waney-edged and other defects - assuming, of course, that Ross is including these in his price (most yards do).

In the past, I've tried to get away with 50% wastage but it is risky.

Some people like to allow 10mm extra to the width of each board so, that may also be worth bearing in mind.

 

[Harbo]

Yes I have to agree - allow for plenty of wastage especially if you are aimimg for wide boards.
You can get away with much less waste if cut into narrower strips specially if the board is cupped?

Rod

 

[yetloh]

I have an Excel spreadsheet which calculates what you need from a cutting list. It has the facility to put in a wastage factor. I find it very useful. If you would like it, send me a PM with your email address and I will send it to you.

Jim

 

[9fingers]

I have an Excel spreadsheet which calculates what you need from a cutting list. It has the facility to put in a wastage factor. I find it very useful. If you would like it, send me a PM with your email address and I will send it to you.

Jim

Jim,

Could I be cheeky and have a copy too?

My email addy is in the footer of this post

Thanks

Bob


EDIT: Oops the forum mail won't allow attachments :roll: :roll:

PM sent

 

[Weirwolf]

100% wastage is a scarey thought :shock: , but I guess only time and Ross can tell what sort of % wastage we will need to factor in. :lol: