How do you get these chair slats the same size

[Alan Lightstone]

Running into a problem I'm having trouble solving. I'm building a Titanic Deck chair, and I've cut out "identical" chair slats from a pattern on a bandsaw, but of course they are far from identical. Subtle, and perhaps not subtle, differences in thickness mostly, and a little in curvature.

How do I get these pieces identical.

I thought of using a pattern bit and a router table, but I can't think of a good way of attaching the pieces together, or to a pattern I can use the bearing to ride against.

I have one side of the pieces sanded identical with my Rotex, but it's now getting the other sides identical that has me baffled.

Here's some pictures of the slats:

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I've been trying to find ways in which I can have the bottoms of the pieces sit securely, and identically so I can just use some rasps and sander to sand the tops, but I can't think of how to get them to sit identically, even though their top profiles are identical.

Any good suggestions?

Thanks.

[Andrew Hughes]

Hi Alan, If you need them to be identical to cut tenons on the ends build a jig to hold each end and make the joint one at a time.If you need them to look the same for aesthetic reasons.I would fit them in their place and shape them.If they vary a little it sometimes adds to a piece.
What is the wood kinda looks like cumaru?

[Mel Fulks]

I agree with Andrew....even though it sounds A LOT like "rearranging the Titanic deck chairs".

[Alan Lightstone]

It's Khaya. Seems significantly less dense than the sapele I'm used to working with, but it works quite well.

It's been a challenging build thus far, to say the least.

I had initially planned to make 2 of them (can't rearrange one chair), but now, I'm not sure.

[Eduard Nemirovsky]

Bandsaw cut little bit thicker, then on router with jig make same size and form.

Ed.

[paul cottingham]

Plane them to the same thickness. Steam them, put them on a form to bend them. A "ladder style" form will let you do a bunch at the same time.

[peter gagliardi]

A nice sharp spokeshave will make lightning quick work out of it .

[lowell holmes]

A nice sharp spokeshave will make lightning quick work out of it .

I agree with Peter.

Lee Valley, Lie Nielsen, Woodcraft, or Highland Hardware can fix you up with a nice one.

[Alan Lightstone]

I actually have the Lee Valley ones, though not sure about technique. I'm messing up the other pieces with my spokeshaves, but doing great with rasps, so I'm using them.

The problem is affixing the parts securely next to each other, so that I can work them to the same dimensions. I was able to get one side, but now doing the other side so that they are identical is what has me stumped as they are so thin.

[Bryan Cramer]

All the above advice is good; this is a common problem with shaping identical parts to match without the guidance of a jig. I think a spoke shave or a compass plane will allow you to make them all identical. For parts like this that are thin but wide I would be more inclined to do a bent lamination rather than saw them. The curve is gentle enough to use standard yellow glue, however my glue of choice is epoxy because of the rigid glue line. When building the one part form you only fair a convex curve once, which, as you found out, is much easier to work than a concave curve. The thicker the plies the more spring back, but you could get away with 1/8" thick plies cut on the band saw. It doesn't matter the exact thickness of the plys because of the one part form, but the thickness of the finished part will all be constant. Even if there is spring back all should spring back the same. Steam bending is a good way to go although it take a bit of practice to get the right results if bending wood is new to you. Hope this helps; it was just a brief explanation of bending.

[lowell holmes]

[QUOTE=Alan Lightstone;2453325]I actually have the Lee Valley ones

So do I. Take really thin translucent shavings. Remember, if it looks straight and square, it probably is. Measure it before you put it to bed.

Practice, practice, practice. See if you can find a class somewhere.

[paul cottingham]

Seriously, if it looks true, it is true. I doubt any of the great contemporary chairmakers use micrometers, or even measure much.
if they are still flat, plane them. If they are curved, spokeshave. The lv one is really easy to set up and use (not talking about the low angle model) is the blade sharp? If you cant spokeshave them, plane the outside curves with a sharp handplane.
i wouldn't beat myself up about the thickness. It wont be super noticeable.

[Dennis Aspö]

What about taping the components together with double sided tape, then cutting them on the bandsaw? Assuming you have the required depth on the bandsaw.

[Alan Lightstone]

What about taping the components together with double sided tape, then cutting them on the bandsaw? Assuming you have the required depth on the bandsaw.

Already cut out roughly the same on the bandsaw. It's the fine tuning to get close to identical pieces that's stumping me.

[Mike Henderson]

The way I've made things like that is to laminate bend them. Cut your wood about 1/8" thick (or less), and enough slats to get the thickness you want. Then make a form and glue them up clamping to the form. You'll get slats that are the same thickness and the same bend. If you're careful in marking your wood, you can have the grain flow across the slats.

I did that on a rocking chair I made. If you want pictures, see my web site.

Mike

[Prashun Patel]

how many slats is it in total?

I have the same problem with curved chair spindles.

If the sum of the widths is less than the resaw capacity of your bandsaw, you can glue up a blank of the slats, then bandsaw it all together, then rip each slat apart from its neighbors after you smooth the entire thing.

I hate pattern routing; it always tears out at the worst places for me. So, if the above is not an option, I try to mark and cut my joinery before bandsawing the curves. Then I just rasp or plane or shave the slats by eye to match a 'master'. If there is any sizeable space between the slats, your eye won't notice subtle differences.

[Dennis Aspö]

Already cut out roughly the same on the bandsaw. It's the fine tuning to get close to identical pieces that's stumping me.

My idea was to cut them all at the same time to get them identical, and then finely enough that only modest surface sanding would be required rather than bulk removal in order to keep them identical.

[Greg Hines, MD]

I have never built one of those, but from what I see on the TV, many people use a router jig to mill each dimension, one for the inner curve, and a different one for the outer curve. As to the edges, rip them on a table saw.

Doc

[Hoang N Nguyen]

I'm sure I'll be running into the same problem you have now so my post is more of a comment/question then an answer. Could you not take the one slat you have already done to your liking, rip it down to a thin piece say about half inch thick and double side tape it to another slat and route with a pattern bit? You can use the thin piece you ripped as the guide for your bearings to ride on and the cutter trim the other slats?

[Rod Sheridan]

[QUOTE=Prashun Patel;2453937]

I hate pattern routing; it always tears out at the worst places for me. QUOTE]

Prashun, how about pattern sanding?

For example a sanding drum in a shaper with a bearing?

Regards, Rod.

[lowell holmes]

When I build rocking chairs, I match the posts with a Lee Valley flat spoke shave and hand planes. Very thin shavings will do it and leave a finished surface. Also, you don't over cut, you can keep things balanced.

[Greg Hines, MD]

I'm sure I'll be running into the same problem you have now so my post is more of a comment/question then an answer. Could you not take the one slat you have already done to your liking, rip it down to a thin piece say about half inch thick and double side tape it to another slat and route with a pattern bit? You can use the thin piece you ripped as the guide for your bearings to ride on and the cutter trim the other slats?

I had not thought about it before, but I have seen that done too. Some will make a pinch block to determine your thickness, and sand one side, reset your block slightly narrower, and then sand the other side, thereby making it parallel to the other side, and all of them would be uniform thickness.

Doc

[Alan Lightstone]

how many slats is it in total?

I have the same problem with curved chair spindles.

If the sum of the widths is less than the resaw capacity of your bandsaw, you can glue up a blank of the slats, then bandsaw it all together, then rip each slat apart from its neighbors after you smooth the entire thing.

I hate pattern routing; it always tears out at the worst places for me. So, if the above is not an option, I try to mark and cut my joinery before bandsawing the curves. Then I just rasp or plane or shave the slats by eye to match a 'master'. If there is any sizeable space between the slats, your eye won't notice subtle differences.


5 slats in total.

I agree about hating pattern routing. Especially with pieces this thin. I'm particularly worried about the safety involved, as I'm not sure how to securely mount them to each other, or a pattern to use on the router table. I'm not thinking that double sided tape is nearly secure enough. I've thought of making holes and either nailing them or screwing them together, but then I have the holes to deal with.

[Alan Lightstone]

I had not thought about it before, but I have seen that done too. Some will make a pinch block to determine your thickness, and sand one side, reset your block slightly narrower, and then sand the other side, thereby making it parallel to the other side, and all of them would be uniform thickness.

Doc

You've got me. What's a pinch block?

[Greg Hines, MD]

You've got me. What's a pinch block?

You make a block that has a slightly rounded edge, and clamp it such that it creates a space between it and your sanding drum, on a drill press. This will allow you to take your strips, presumably slightly thicker than you need, and sand one side of each slat. Then, you adjust the block very slightly, and run the opposite side of the slats to make them uniform in thickness. I wish I could find a photo, but its not that hard to figure out. Think of it as similar to a bandsaw fence that is a single point, used for resawing.

Doc

[Prashun Patel]

Securing the pattern isn't the issue. You can certainly doublestick tape it. It doesn't require that much of a bond.

Pattern routing just gets tricky for me on the entrance side, end grain, and near grain transitions on curves. But then again, I don't a spiral flush trimming bit...

Given that your parts are already cut - and given that chairs might be the kind of thing you'll want to make more than one of - I would invest in the right pattern bit, and make a pattern routing jig. You can use toggle clamps and a wide sled.

[Mike Schuch]

Could you use the concave cut off piece as a fence clamped to the table on a spindle sander or drill press table with a drum sander to sand the slats to a uniform thickness?

[lowell holmes]

I've used a combination of hand planes and spoke shaves to do what you want to do.

Practice on some scrap wood. You will be how close you can come, and oh by the way, have fun doing it.

[Dennis McDonaugh]

The way I've made things like that is to laminate bend them. Cut your wood about 1/8" thick (or less), and enough slats to get the thickness you want. Then make a form and glue them up clamping to the form. You'll get slats that are the same thickness and the same bend. If you're careful in marking your wood, you can have the grain flow across the slats.

I did that on a rocking chair I made. If you want pictures, see my web site.

Mike

That's the way I make the backs of a chair.

[Brian Holcombe]

To cut to identical width

Use a series of battens clamped or held with holdfasts to your bench to hold the work. Use a handplane on it's side to joint one edge. Mark the width with a knife gauge, then joint the other side with the hand plane. Repeat for each slat.

For thickness I would mock up a form to hold them then plane the outside with a #4 plane until the outside is clean. Mark the thickness with the marking gauge then cut the inside with a radius plane.

Miter the edges.

Then your done....and if you set the planes well you wont need to sand either.