Cutting green oak sleepers with a bandsaw

[petercaldwell]

Hi,
Looking for some advice. I need to cut down some 8ft long 8x4 green oak sleepers into 1 inch boards using a bandsaw ( Axminster 350). I'm looking for advice on blades and how to cut straight and minimise 'wander'.
Many thanks

 

[MikeG.]

It's the wrong piece of kit in the first place, and the wrong job. With big lumps of oak, you take the tool to the wood, not the other way around. You won't get anything at all useable from the process even if you could achieve it. If I showed you photos of my off-cuts (of that size or bigger) from all the green oak work I do, you'd never believe the shapes they contort themselves into.

 

[petercaldwell]

Sorry, I should have said the oaks been air dried for about six years

 

[MikeG.]

Well you actually said the exact opposite, by saying it was green!

What are you trying to achieve? What are the 1" boards for? Are you wanting 8" boards, or 4" boards?

 

[beech1948]

I've cut down larger timbers into 2" thick pieces a few times. Just seen that its green oak. Cutting this into smaller 1" thick pieces can cause lots of cup/twist/bow. The outside may look dryish but the inside will be dripping wet. I have seen liquid literally run out of timber like green oak.

Consider the timber choice carefully. Why green oak. It will move a lot after the cut. Might be an idea for you to tell us what you want to use it for.

Just seen MikeG's message. In principle he is right. Take tools to the wood. A hobbyist may work differently and take different risks but safety is paramount. Consider can you get the seller to cut it for you.

First is does your bandsaw have any drift. If not OK. If it does then fix the issue by adjusting the bandsaw ( You tube videos will show how) so drift is removed. Drift is a sign of a bandsaw in need of adjustment. Good idea to tune the bandsaw for this job. Be sure your bandsaw can cut an 8x4 piece and is powerful enough to keep cutting for 8 to 12 feet. Yup some assumptions there already.

If cutting through the 8" depth then I would want to use a minimum 1" wide blade and possibly 1.5 to 2" or more. That will be your first problem. If a hobby bandsaw then it will not tension a blade more than 1/2" wide. Yes the manufacturer will say 3/4" but they all lie like crazy about blade tensioning ability.

Set up a rest/support about 4 or so feet from the front of the bandsaw table and at least 4ft from the rear of the table

The timber is too big for a one man operation get some help with handling the 8x4 both before the cut and after. If the timber is wet at all then the weight may be doubled and hard to handle

Practice loading, getting the timber aligned and pushing it over the table and off the other side. It can take a lot of effort and the weight can catch you out.

Blade needs to have the minimum number of teeth in the wood. Thus a ripping blade of say 3 teeth per inch or better yet 2 teeth per inch. If a hobby bandsaw then it is unlikely to tension anything bigger than a 1/2 inch blade which will limit the available selection of blades. Call Tuffsaws and discuss. If only 1/2" then be careful to cut slowly enough to give the blade time to clear the sawdust but not so slow as to burn the wood.

If task is a one off then a normal steel blade will be OK. If a repeating task then consider an M42 style blade. Stellite blades would be too expensive and too much for this task.

If a repeating task then consider getting a business to cut for you.

Your blade guides may end up quite high. In that case fix a 2x4 with clamps across the table and use it as support. Old style and a bit crude is often better than flash new aluminium fences. Clamp at both ends.

Finally your not going to get 1" boards out of this without a lot of waste. An 8x4 may not be exactly that measurement. When cutting the blade kerf on a hobby bandsaw will consume around 3 mm so if cutting through the 4" deep side then 21 to 28mm will be lost due to 7 cuts at 3-4 mm. If you put these through a planer/thicknesser then more is lost as well. A 1.25 inches thick the rough cut boards would yield a 1" thick planed plank.

If it were me I might rethink this as I'm not sure you will get what you want out of the 8x4s.

Good luck. Hope the above is useful.

Stay safe.

 

[beech1948]

Air dried for 6 years. Still 20 to 30% moisture then.

 

[deema]

The old rule of thumb is 1” per year for air drying. At 4” thick it should be nicely seasoned for use in an environment that isn’t centrally heated. I would personally expect if it’s been properly stacked for it to be at around / just below 20% moisture content.

If you have a few sleepers to cut down, I personally would load them up and head to the nearest yard with a proper resaw and get them cut down on that. It shouldn’t be very expensive and will give you consistent product at the end.

I’ve resawn 8” of oak on a bandsaw a number of times, the biggest issue is handling the weight, and managing to feed it consistently without it wobbling over. You will need good supports both before and after the Saw so that you are only advancing / guiding the stuff and not holding onto it and supporting it. If you have the stands / infeed table and outfeed table you really only need a minimum of a 3/4” inch blade 3 tpi, fairly slow speed on the saw to avoid the blading overheating and plenty of tension. You will need to allow a minimum of 1/4” or 6.35mm (I’ve been told off before for using proper British Units rather than the French system!!) over your planned size for planing and straightening.

Be aware that the stuff could move considerably as you start to cut through the sleeper if it’s not been stacked properly and ther is still a moisture gradient creating tension. Once cut it will need to be placed in stickers and kept away from any light / heat source as it restabilises the moisture content. Be prepared for it to move.

 

[petercaldwell]

Thanks for that deema. Can i ask where you took yours to be sawn, I'm not far from you if you're in chester

 

[deema]

I use Chris Kirby for my oak supplies. He’s brilliant IMO. His yard is down a long ‘dirt track’ and it’s within a farm complex....like me I’m sure if you pop around you won’t believe that he gets lorries down it!! . He does a lot of timber framed buildings, and is unbelievably obliging, but a man of very few words.

He has a few resaws that can handle anything. I’ve used his resaws on a number of occasions.

Tel ‭+44 1829 260091‬
Oak Timber
Spurstow
Tarporley
CW6 9RS

 

[MikeG.]

If you are after seasoned 1" oak boards, why not buy seasoned 1" oak boards? They're all properly stacked and dried, and all the movement that is going to happen has already happened. Sawing up a big lump like this runs the risk of producing nothing useable at all.

 

[petercaldwell]

Mike,
I get the impression that you think this is a bad idea. I own a forest, I cut down some oak trees and roughly cut them to sleeper size with a chainsaw, I now want to make a kitchen out of them. I don't just buy 1" oak boards as I like the idea of using my own timber and this way its free. I'm sure you make stuff out of wood for much the same reasons

 

[Ttrees]

Not with that machine surely though !


Is these sleepers big enough to obtain quartersawn stock form them ...
and are you after the figure, or rays that comes from quartersawn oak ?
You wouldn't need to worry much about stability if it were

Tom

 

[MikeG.]

Yes, I did think it was a bad idea, until you gave us all the info. You'll lose much of the timber. But, since you own a forest, what would be a bad idea for most people isn't a bad idea for you. You presumably don't care if you lose half the wood or more, as you've got plenty more where that came from. You didn't actually give us all the relevant information, and ordinarily, it is a really bad idea to A/ resaw large sections of timber like this down into thin boards, and B/ to do it on inappropriate equipment. I own exactly that bandsaw. It isn't up to doing the job you propose.

Seriously, though, if you own a forest, cut some decent trees now, plank them, and stick them. In a year or two you won't be considering such a low-return operation, and you'll have some decent timber to use for joinery.

 

[PAC1]

There are people who have mobile milling machines if you cut down half a dozen trees it is economical to get them to come and plank it up for you.

 

[AJB Temple]

Hi. I have somewhat got the T shirt on this as I have had very similar circumstances. I handle a fair bit of oak (not professionally) for timber framing, making a couple of bridges etc. I had a large stock of seasoned oak in beam sized chunks. I harboured ideas of dimensioning it on a band saw and frankly it is a right pain to do. Unless you have a really big saw, and a really good roller table, you will find it a nightmare to handle the wood, which is seriously heavy, with enough precision to do a good job. You will also knacker a lot of blades.

If you are doing a fair quantity I would get myself a 12" portable circular saw (as used by framers). This should give you a 5" depth of cut and will deal with most things in two cuts. This is FAR quicker than messing about with a bandsaw as you can rest the oak on a trestles, cut and flip. It will do a neater job in much less time. The Makita 12" is a good saw (bit expensive) and there are other alternatives that you can get from the US.

 

[deema]

I don’t share the pessimism towards your project or the way you have so far approached it. I think it’s a superb opportunity to have a kitchen that’s really part of the surroundings.
I may be wrong but I suspect your aiming for 3/4”finished size if your making a kitchen from them. So, you will get circa 7 off 4 “ wide boards from each piece. This will be a good width for jointing up into panels.

A kitchen is a very hot dry environment and the oak planks will need to be acclimatised and dried out further before you start to use them to make the kitchen. Ideally they need to be kept somewhere that is both warm and has about the same humidity as the house / kitchen. The moisture content needs to come down to circa 12% or stabilise at a lower figure. 12% is about as low as you can get with air drying. With 1” thick planks this won’t take too long as they have already dried out considerably. Plane them up only after they have reached a stable lower moisture content.

If they are kept in sticker for this period they should remain fairly straight. If any twist during this period it’s good to know as a board that twists will always when ever it moves twist again. You can plane them flat.....but they then will twist with the season! These are best used for non critical, not on show stuff and preferably in short lengths. A trick to use them ‘on show’ is to go to the lengths necessary to make the panel two ply thick. It’s got me out of a jam where I’ve run out of stuff and needed a match.

 

[dickm]

If you've got a forest, then presumably you are going to be cutting a fair bit of timber over the years. A Forestor or similar portable band mill might therefore be a good investment - costs a lot up front, but will sell for sensible money afterwards. Or, if you can afford the wastage, Alaskan mill and a big, powerful chainsaw.
Like several others, I'd be s**t scared of trying to do what you are suggesting with any "domestic" bandsaw; wouldn't attempt it on my 352, which is at the top of that band.

 

[Mark A]

I've sawn similar sized pieces of timber with a circular saw, as AJB suggested. My largest saw takes a 10" blade, and has a cutting depth of around 3 1/2", so I ripped along opposite sides and cut the narrow strip of timber connecting the kerfs with a reciprocating saw. This method is fine for occasional cutting, but if you have a fair amount then I'd look into other ways.

 

[Mark A]

Just a thought...

If you have the space and power supply then large resaw bandsaws pop up on bidspotter from time to time.