HELP NEEDED - Mitre Joints

[andy2306]

Help,

I am fitting a picture rail in my living room and all was well with the 45 degree mitre joints, however, I then came to a wall whose overall angle to each other was 110 degrees I thought no problem two 55 degree mitres will go the trick.............. ooooops wasted picture rail.

How do you cut mitres for non standard 90 degree corners? I also have one corner that is less than 90 degrees

Is it possible to do this with a macallister compound mitre saw?

Andy

 

[Space cat]

I thought no problem two 55 degree mitres will go the trick..............

Two 55° mitres will indeed do the trick - unless you cut 35° ones by mistake! I cant help you with the saw question because Ive never had one. For a one-off job, I would use an angle gauge and a hand saw. (I once cut three lengths of handrail for a loft staircase this way.) To be on the safe side I would cut the angles slightly oversize then sand down to fit.

 

[2scoops0406]

Presumably theyre internal mites? if so scribing would be better, rather than mitreing.

Internal mites??? mitres even.

 

[regsmyth]

Presumably theyre internal mites?

 

[andy2306]

What would be the advantage of scribing the joints? I thought that a mitred joint would be much cleaner?

 

[2scoops0406]

With a scribed joint, you don't have to worry (so much) about the angle the pieces join at. With a mitred joint you have to cut exactly the right angle, and either assume the wall run true in the vertical sense to each other, if not you can end up with a tricky compound cut. Skirting board internals are usually scribed, I can't see why that would be different for a picture rail.

 

[big-all]

Help,

I am fitting a picture rail in my living room and all was well with the 45 degree mitre joints, however, I then came to a wall whose overall angle to each other was 110 degrees I thought no problem two 55 degree mitres will go the trick.............. ooooops wasted picture rail.

How do you cut mitres for non standard 90 degree corners? I also have one corner that is less than 90 degrees

Is it possible to do this with a macallister compound mitre saw?

Andy

hopfully a simple explination for those still confused
lets assume you are mitering to the right and using 90deg 45deg is of course central between the 90 degree point and the fence[back support]

now when you mitre to 110 deg you are increasing the arc to the left by 20 degrees so half the 110 is 55 but because you have only extended to the left you have to move half the difference to the left
so half the 20 is 10 so from the 45% point you need to go left10 deg downto 35degrees


clear as mud eeehhh

and scribing internals is the best method for picture rails and dado rails

although because they are only a half to a quarter the width out of angle joints are less of a problem
although shrinkage gaps will still be as large

 

[andy2306]

Yeah, I eventually worked that out, I basicallly thought of it as, measure the angle, then work out the angle rerquired to make 180 and half that angle, bang the joint was done!!!