Thread: Table chamfer,shape, or join first ?

I would joint and thickness all the boards and glue them up before adding chamfers or bows(not really sure what you mean by bows)
You only need two or three dominos per joint for alignment. The glue will hold it all together.
Chamfers can be added with a hand plane.

Hi Rich, generally first process is boards flattened/thicknessed with edges square, flat and straight or preferably with a slight concave curve and done with a hand planed, time spent here to get edges square pays in ease of glue up and a tight join, glue boards then all shaping to edges done, the bow I think you are talking about sounds like a concave curve on both long sides of the table, as it would be easier to do this as a single board using the bandsaw before gluing this would be the only operation prior to glue up, the important thing here is to the alignment of each outer board relative to the others otherwise the curves may endup offset, a little bit may not matter, I would mark a center line on the boards after you are happy with their location and then mark out curves relative to that center line, should be able to glue up in one hit but make sure everthing is setup, I would suggest a dry run to iron the bugs out, for the edge treatment there may be a router bit at the 20° that you want otherwise set powersaw at 20° for the ends, for the curves may have to look at hand tools if no 20° bit available, belt sander held at the angle might work too,
Let us know how you go and do some piccies


Pete

Doubt that you could get a 20 degree bit without having one custom made. However 22.5 and 15 are available if you look hard enough, used for mitre cuts for 45 degree and 30 degree corners.

Hi Rich

Originally Posted by Bunwoody

Im starting to joint 7 @ Jarrah 170x32x3m boards to make a table top approx 1.2m x 3m. Just having some indecision as to the order to do the top construction as I want to end up with the long sides having a 50mm bow out in the middle, and with a 20 degree chamfer on all 4 edges. Can I have some comment on my proposed construction order
1. Joint and thickness boards -- definitely
2. Shape the bow on the outer two boards using the bandsaw -- don't. Make up an extra long template for the bow. Make sure the curved edge of the template is square and smoooth
- should I cut the chamfer as well now ? NO
3. Use 10x50 dominos every 300mm - should the slots for these be the tight setting, or loose or a mix of both ?? -- the Dominos are only there to help with alignment. You could use 5 or 6mm ones located in the centre of the joint. If you do use then, the spacing can be about 500mm. Make the slots in the board to the left of the joint tight, those in the board to the right with the widest setting, and make sure you always reference from the show face of your boards
4. Use techniglueCA and clamp together in two operations using the bandsaw offcut to clamp on the bowed edge. Or should the top be glued up in one hit ? I have made some scissor action clamps as well as the Bessey Ks so can do in one hit - just thinking about the time to put dominos in and glue up in one hit. -- don't glue the Dominos, just insert them into dry slots. Practice your glue up and decide if you can easily manage it all within the open time of the glue. If not do the glue up in stages
5. Cut top to length with 185mm circ saw set at 20 deg -- NO use the saw set at 0°. Then clean up the saw marks either by hand sanding or with a hand plane.
then use the template to mark out the bow, cut outside the line with a jig saw and clean up with your router guided by the template. If your router has the guts, you can cut the bow entirely with the router
6. Somehow use hand router to chamfer the sides - any ideas on how this can be done ?? -- use a hand plane a #7 with a sharp blade will have all the mass you need to make this task easy. Do the ends first, use a pencil to mark out the two edges of the champher, work the endgrain from the outside edge towards the centre -- this will prevent tearout.
Do the long edges the same way working with the grain.
If you don't have a #7, a #5 will do.
Your advise would be appreciated.
Rich.

Thank you for the advice ! In my original e-mail I have not been too clear about the table shape - probably best described at oval sides, with a bevelled edge ?? as per attached sketch. To achieve the bevelled edge I didnt know if it was possible to attach a 20deg half moon wedge to the base of my router and use a straight cutter to achieve the bevel ??

Originally Posted by Bunwoody

Thank you for the advice ! In my original e-mail I have not been too clear about the table shape - probably best described at oval sides, with a bevelled edge ?? as per attached sketch.
To achieve the bevelled edge I didn't know if it was possible to attach a 20deg half moon wedge to the base of my router and use a straight cutter to achieve the bevel ??

I figured you meant an oval shape.
Do you intend the bevel to be on the top or underside of the top? The underside is more usual but your sketch is a little unclear

Yes you can attach a wedge shaped base to your router and use a straight cutter, but please don't. Table tops would usually have a 5-6mm roundover transition from the top to any bevel. Cutting the bevel and then creating the roundover transition is very straight forward and quick with a sharp hand plane, but very tricky to do well with a hand held router as you have nothing to guide the router.

I have seen a table on the net I like the shape of, so thinking of similar leg and top layout, but with the oval shape on the long edges. I have an old #8 plane is this ok for the bevel ? Thinking of getting a HNT A55 trying which might be more suitable.

Bunwoody,

If you follow what Ian has said then you can't go wrong. Don't forget to show us some photos.

Hi Rich
that's a nice looking top you linked to. Its champhered edge looks like what's called a natural edge which because of its texture is usually arranged as shown. The ends appear to be vertical, i.e at 90° to the top.
With sawn boards you have a choice of having the champher on the top or underside -- I suggest you consult your primary client and ask which they would prefer

A #8 might be a bit tiring to use -- I don't know how much time you spend in the gym -- but ptovided the blade is sharp and the plane in tune it should easily handle the champhering job, plus remove the saw marks from the ends (just remember to work the cross grain from both long edges to the middle).

Ian - yep the plane will give me a workout - but I dont have to finish it in a day ! The customer is my wife so after waiting two years for the table I think any table will be welcomed. We went for a drive to Margaret River and saw a few tables in galleries, and the bevel on top of both sides and ends, even on sawn boards looks awesome - it sort of matches the leg profile.
Going back to your advice on the actual construction, the only bit Im not sure about is the poor old jigsaw trying to do a 3m cut in 32mm Jarrah to get the bowed edge. I might cut the two outer boards close to shape on the bandsaw, then use the offcut pieces to help with square clamping at glue-up, then cut the bevel by plane after glue-up. Thanks Rich.

Originally Posted by Bunwoody

Going back to your advice on the actual construction, the only bit Im not sure about is the poor old jigsaw trying to do a 3m cut in 32mm Jarrah to get the bowed edge. I might cut the two outer boards close to shape on the bandsaw, then use the offcut pieces to help with square clamping at glue-up, then cut the bevel by plane after glue-up. Thanks Rich.

my experience is that with the right blade, a jig saw will easily cut Jarrah that thick. Last time I did it I used a Festool Trion S 75/4 FS blade.

The only issue I can see with cutting the oval first is keeping it uniform. You won't cut the table to length till after glue up so there's a real risk that the midpoint of the belly will become off-set

Originally Posted by Bunwoody

Thinking of getting a HNT A55 trying which might be more suitable.

should have commented
get yourself a block plane as well. Set very fine, and held in the hand it will make blending the top to the champher a breeze

Ian funny you should mention the block plane - I added one to my HNT group buy order yesterday morning ! I would love the chisels as well but the planes and setout tools have killed the budget already.
Point taken regarding centralising the bow after trimming the ends. I will try my K-mart Bosch jigsaw on an offcut first and see how it goes.
Cheers Rich