flattening boards

[markblue777]

Hi all,
Yesterday i was flattening some boards for some shelving in the house. They had a cup on them i would say of around 3mm (the gap from cup to flat surface when laying cup side down).
My question is how long does it take to make the board flat.
I was using a number 7, should have i been using my number for to get the bulk off? It just seemed like i was getting no where.

I take it once i have the boards flat i should then do the edge for jointing as it will lead to a better result. I was becoming frustrated and gave up and glued them up so they are still cupped a bit but thought it may be easier to flatten now they are glued up.

They are going to be more rustic looking shelving so can get away without looking perfect but i have some scrap now that i want to practise on and get this technique down. That way i can use the scrap for shelving in the kids room and make a small bedside table for them as well.

A point to note is that i work off a work mate with some mdf screwed to for my bench so have no real way to clamp it without using quick release clamps. Am i better off trying to make a wedge system to hold it to the bench so i can plane the length.

Cheers
Mark

 

[baldpate]

I don't think a jointer (No7) is the right to plane to start getting a cupped (arched across it's width, right?) board flat - too long, and probably tuned to take fairly thin shavings. You needed a shorter, coarser plane to start with - in other words a jack plane, but a No4 with a well cambered blade will do.

Start with the board concave side down; some battens to your MDF work surface (one long side and two ends) to hold the workpiece in place as you plane - I'm assuming your MDF surface is bigger than the workpiece. With a pencil, mark the upper (convex) surface with a coarse cross-hatch. Working diagonally across the workpiece (i.e. using strokes at 45 degrees to the long side grain direction, and progressing along the board) start removing material from the centre of the board (the highest point). You should change the direction of the diagonal occassionaly, and/or flip the board end-to-end - helps eliminate bias in your planing technique. The pencil marks will disappear progressively as you remove material, indicating where you've flattened the board. Keep going until the marks are gone; but towards the end of the process, start checking that you are getting the board flat along it's length, and that you haven't introduced twist (wind), and adjust accordingly.

You should end up with one face which is fairly flat, without cup, bow or twist. The surface finish will be fairly rough, however, so now you can take your jointer to it (working along the length) to finish it. This gives you one flat reference surface from which to judge how much you need to take off the other side to get a flat board of consistent thickness. Mark that thickness round all four edges, flip the board, and repeat the flattening process (this time you'll be removing material from the long edges inwards, the centre-line of the board being the lowest point). This time you can work down to the thickness line gauged around the edge.

A workmate isn't ideal for this sort of job - a lot of force is exerted when you are removing material diagonally, so an unfixed workmate will dance all over the place. Try and brace the far side of the MDF worksurface against a wall, or some other immoveable object.

How long does it take? It depends on your skill, the size of the board, and the wood species, but it's not a quick job. I always find it takes me quite a long time, but then I'm not very skilled. It's also quite hard work! I wish I had a planer/thicknesser!

Chris

 

[JohnPW]

Yep, for taking off a lot of wood, it's quicker to use a short or medium length plane with a cambered blade, ie not sharpened straight across, to take thick but narrow shavings.

 

[markblue777]

Hey baldpate,
Thanks for the explanation i will give it a try and see what happen. I put a length of board across the bottom of the work mate and a couple bags of sand, I find it keeps it fixed quite nicely. I will get the number 4 out and have a go with that.

If i had spare time for the project I would not have worried but I was trying to get as much done as possible due to space limitations for the timber. So when you are spending a while to flatten boards you just assume your doing something massively wrong (especially when youtube videos lead you to think its a 5 minute job haha) Anyhow I will have another go and just know that it is not necessarily a quick turn around.
Cheers
Mark

 

[morfa]

Those youtube videos are normally posted by people who've been using handtools for years. Paul Sellers for example, he's been going for 40 years and had a proper apprenticeship to some seriously good craftsmen.

I often spend an hour on a small board. I've recently done a big worktop, 70cms wide, 2m long and that took me about 3 full evenings to do. And the smoothing took another evening or two as well. However keep on persevering, it's not that hard once you've got the hang of it and that doesn't take ages to do. I've probably flattened about 20-30 boards now and it's definitely getting easier.

However as others have mentioned you need a no 4 with a cambered blade. Or ideally a no 5, again with a cambered blade. A proper bench would help as well. Things go so much quicker since I built my bench and stopped using a workmate.

 

[markblue777]

Hi Morfa,
Yeah think i will have to borrow a #5 from my grandad he has a few in his garage (or camber my #4).

Yeah I would like a bench really but not the space to be able to do something though at the moment.

I will be making a couple of small 4ft high sheds soon as our existing one is coming down (due to it rotting away),
When doing that I think I will do it with have a bench in it and storing bits under it / on it, even if I can make it just 4ft long it would help a bit, but for now I will take what I got from here and give it ago.

Cheers
Mark

 

[custard]

Mark, don't get too hung up about the type of plane. Much more important is how you use it. Apprentices at the Barnsley Workshop only use one bench plane, a number 7, so don't fall into the trap of thinking that a different plane would solve your problems, you've got everything you need.

The fastest (and easiest) method of stock removal is by planing across the grain. Either straight across if you don't mind a bit of tear out at the far edge, or planing at 45 degrees which will reduce the tear out. Set the board with the concave side uppermost, and use little wedges or bits of scrap to stop it rocking. Set your plane for a fairly coarse shaving, wax the sole of the plane to reduce the effort, and off you go!

 

[Silas Gull]

Mark, don't get too hung up about the type of plane. Much more important is how you use it. Apprentices at the Barnsley Workshop only use one bench plane, a number 7, so don't fall into the trap of thinking that a different plane would solve your problems, you've got everything you need.

The fastest (and easiest) method of stock removal is by planing across the grain. Either straight across if you don't mind a bit of tear out at the far edge, or planing at 45 degrees which will reduce the tear out. Set the board with the concave side uppermost, and use little wedges or bits of scrap to stop it rocking. Set your plane for a fairly coarse shaving, wax the sole of the plane to reduce the effort, and off you go!

Amen to that.

 

[baldpate]

custard - it's interesting you say start with the concave side upwards. Is that standard practice, or just personal preference? Any particular reason? In my (albeit limited) experience, I've found it easier to start on the convex side - perhaps because I find it easier to shim if it rocks a bit. Have I been doing it 'wrong'?

 

[custard]

custard - it's interesting you say start with the concave side upwards. Is that standard practice, or just personal preference? Any particular reason? In my (albeit limited) experience, I've found it easier to start on the convex side - perhaps because I find it easier to shim if it rocks a bit. Have I been doing it 'wrong'?

Hello, I don't think there is a right way or a wrong way, but the OP is using a No 7 plane which is long enough to ride across the "rim" of a concave board, which would then make the exercise pretty much automatic, when you're cutting all the way across you're done, until then press on!

For someone like yourself with more planing experience running across the grain on the convex side has the advantage of limiting any tear out (you're only cutting in the centre of the board so you're cut is effectively backed up), but for someone with a bit less experience there's a risk you'd just follow the curve of the convex side all the way across, therefore making the board thinner but without actually eliminating the cupping. I do concede that at some point both sides of the board need to be tackled, but as the OP was clearly getting frustrated at lack of progress I thought achieving an early win might be the most important thing.

Anyhow, that was my logic, but the thing I was really trying to address was that you don't need to spend money on more planes to flatten a board, a No 4 or a No 8 will both get the job done.

 

[markblue777]

thanks for the information people, I will be putting everything said into practise.
cheers
Mark