kerf loss

[Big Beech]

I've a thin board to resaw for a friend, what is the kerf loss on a 3/8 chain please?

Wondering if it would be better to get someone to run it down on a bandmill instead, though i am not sure if they would be happy as its been kiln dried about 7 years ago and been indoors ever since ?

Edited October 4, 2020 by Big Beech

[Jamespepperpot]

3/8th is about 8-9mm wide roughly but the kerf might be slightly more. I usually account for 10mm because of the finish from a chainsaw chain. A narrow band bandsaw mill is usually around 2mm. It will cut seasoned wood fine with a sharp band, they'll just have to take it slowly and use a lot of water to keep it cool.

[Forest2Furniture]

1 hour ago, Big Beech said:

I've a thin board to resaw for a friend, what is the kerf loss on a 3/8 chain please?

Wondering if it would be better to get someone to run it down on a bandmill instead, though i am not sure if they would be happy as its been kiln dried about 7 years ago and been indoors ever since ?

Splitting an already thin board into two thinner boards may not be a good idea as the boards are likely to move a lot.

When you machine a thin board thinner it's normally done on a thickness planer and equal amounts are taken of each side of the board to reduce movement, by cutting the board in half you're releasing tension/compression on one side only which will lead to greater movement.

[Big Beech]

28 minutes ago, Forest2Furniture said:

Splitting an already thin board into two thinner boards may not be a good idea as the boards are likely to move a lot.

When you machine a thin board thinner it's normally done on a thickness planer and equal amounts are taken of each side of the board to reduce movement, by cutting the board in half you're releasing tension/compression on one side only which will lead to greater movement.

Depends on the definition of thin, but this board is currently 72 mm thick. He is wanting to divide so he can do a river table on some Burr Yew.

[Rough Hewn]

Do it, but have a caveat that if it warps you’ve already warned him.
After 8 years it should be fairly stable.
[emoji106]

[Rough Hewn]

And yes James is correct about 3/8 kerf being 10mm.
[emoji106]

[Dan Maynard]

Warping depends how wide the board is too, surely? Might not be that big if burr yew.

[ucoulddoit]

I recently re-sawed a 3" (80 mm ish) x 400mm x 4m kiln dried oak plank into two thinner planks with my Alaskan mill, and reckon I'll end up with a thickness of 20 to 25mm once they've been left a while before final planing. I'd thought I'd easily get 30mm, but it's surprising how the slight warp and twist along the length of the original plank will lead to more waste than expected. Fortunately the two planks have barely warped after being split apart which are an indication of slow and careful seasoning, but not by me! 

 

Andrew

[ucoulddoit]

24 minutes ago, ucoulddoit said:

I recently re-sawed a 3" (80 mm ish) x 400mm x 4m kiln dried oak plank into two thinner planks with my Alaskan mill, and reckon I'll end up with a thickness of 20 to 25mm once they've been left a while before final planing. I'd thought I'd easily get 30mm, but it's surprising how the slight warp and twist along the length of the original plank will lead to more waste than expected. Fortunately the two planks have barely warped after being split apart which are an indication of slow and careful seasoning, but not by me! 

 

Andrew

Just thought I should add that when re-sawing this plank with the Alaskan mill I used a guide ladder carefully wedged off the top of the plank so it was as near straight and twist free as possible. So the re-sawn faces are virtually dead straight and not twisted which I wouldn't have achieved if I'd just run the mill along the top face of the plank. That provides a good start for planing to thickness. It's not often I need 3.5m + long planks that are dead flat and straight and shorter stuff is a bit easier and less wasteful.

 

Andrew

[Big Beech]

Yew is a very stable wood ive found, so ill take the gamble.

Board width varies but average 350mm id guess