Hardwood Worktop Jointing

[twm]

Hello, I've got to do a 90deg join in some solid wood worktops with a rounded edge. I've read through various postings but not found a definitive answer (if there is one?).

To me, I have a few options;
1. 45deg mitre
2. router and jig
3. hand cut mason mitre

The 45deg join seems the simplest but its a large cut and not sure if i like the look.

router and jig - is this a viable option for solid wood due to expansion etc.. I've used it on laminate before so confident on trying it on solid wood

hand cut mason mitre - when i say hand cut i mean that i take a section of the rounded edge, ending with a 135deg cut to form the female part and i then just cut a 135deg section off the rounded edge of the other length of worktop to form male end.
see http://www.diydoctor.org.uk/projects/mitering.htm
Is there any difference in this than using the router and jig. The jig forms a slightly rounded mitre where as this has a straight mitre?(if that makes sense)

I would like to do the hand cut mason mitre as i have the tools (circular saw, handsaw, fine sandpaper) but can get hold of router and jig if its the preferred cut.

If there are other options then let me know.

I also wanted to know your opinions on fastening the join.
Should you always use under mounted bolts?
Are biscuits better?
Can you use metal plates?
What glue/sealant should be used?

Any advice would be most appreciated.

 

[mr_mike]

Hi twm,

For a good 4 page doc on joining & fixing wooden wortops, plus answers to your other questions.....visit :

http://www.hardwoodfloorstore.co.uk/worktops/worktop_installation_1.htm

For a good explanation of using a router & worktop jig......visit :

http://www.raygirling.com/wtjig.htm


Hope that helps ! (Certainly saves a lot of typing....)

 

[Scrit]

The 45deg join seems the simplest but its a large cut and not sure if i like the look.

Very wasteful of materials and you really need to shoot the joint with a jointer (#7 or #8 plane) after sawing

Router and jig - is this a viable option for solid wood due to expansion etc.. I've used it on laminate before so confident on trying it on solid wood

Bob on with the problem. Wood expands and contracts in service. It does so at a different rate across the grain to the rate with the grain. That is why man invented to frame and panel door - to accommodate this feature if wood. A butt scribe and mitre joint (or mason's mitre) clamped-up tightly with worktop joiners will open over time unless provision for movement is made. BTW the same goes for how you fix the top onto the carcasses.

Hand cut mason mitre - when I say hand cut I mean that I take a section of the rounded edge, ending with a 135deg cut to form the female part and i then just cut a 135deg section off the rounded edge of the other length of worktop to form male end.

Will work a bit better than the mason's mitre as the mitre will be very shallow (3 to 6mm?) as opposed to 30mm or so for the routed joint. Less to show up when it moves.

Personally I use a loose plywood tongue the entire length of the joint and seal the ends with PU sealant. The joint is then clamped-up using metal plates on the underside - the plate slots are slightly oversize from the screws which allows for movement - the plate nearest the front edge is screwed through the drill holes with larger diameter screws so that has no allowance for movement at all. The problem is always that even a small mitre can open up.

The absolute best quality way is to rout and chisel away a 6 to 10 mm square rebate in the front edge of the worktop which runs through to the wall. Glue-in and plane square a matching fillet to give you a square edge. Butt joint the worktops together. Round over the small lenth of exposed square timber with a router and round-over bit. Finally (if required) using gouges to hand cut back the mitre in the round-over by the joint. When this moves, it isn't so obvious and if it moves badly it can be easily rectified. More work, I know, but it just looks so much better

Scrit

 

[mr_mike]

The absolute best quality way is to rout and chisel away a 6 to 10 mm square rebate in the front edge of the worktop which runs through to the wall. Glue-in and plane square a matching fillet to give you a square edge. Butt joint the worktops together. Round over the small lenth of exposed square timber with a router and round-over bit. Finally (if required) using gouges to hand cut back the mitre in the round-over by the joint. When this moves, it isn't so obvious and if it moves badly it can be easily rectified. More work, I know, but it just looks so much better
Scrit

By jove, he's right you know ! But, not to be attempted by the faint-hearted !

 

[twm]

cheers guys,

think i'll go with the mason mitre.

i'll nip the 135deg mitre off the rounded edge, measuring about 10mm back from the tip of the round over to form male section, offer this up to the female side and mark around the edge.

once marked out i should be triming off about 10mm or so of the round over edge with the circular saw(or should i rout it?) then hand cut the 135deg angle for the mitre to get the female. if need be i can take a bit more off to fine tune.

does that sound correct?

would you recomend bolts or plates for joing the above?

 

[Scrit]

By jove, he's right you know ! But, not to be attempted by the faint-hearted !

I don't think you can accuse me of that

Think I'll go with the mason mitre.......

....once marked out I should be triming off about 10mm or so of the round over edge with the circular saw (or should I rout it?) then hand cut the 135deg angle for the mitre to get the female. If need be I can take a bit more off to fine tune

Saw the female mitre first, then rout away the majority of the waste and finish with a chisel and/or bull nose plane - then cut the male side of the joint. That way if you have a problem (such as chipping out) and need to deepen your female cut out, the male doesn't have to be reworked as well. To trim the mitre faces you should ideally make or buy a mitre trimming template (and at the price of those I'd make one) to support your chisel whilst you pare the mitre (a sawn cut is going to be a tad rough).

Would you recomend bolts or plates for joing the above?

Plates - bolts will not allow your timber to expand or contract. One plate needs to be fixed, the others need to allow some movement which either means slotted plates or using screws (round heads) with smaller shanks than the holes in the plates to allow things to move a couple of millimetres.

Scrit