mitre probs

[kaseryn]

Hi all. I'm trying to lay some trim along the edge of a room i tiled. I wanted to make a good job of it and follow the turns around the door frames and thought this would just be a matter of 45's all round.. but that doesn't seem to be working out. Picture below.. i know those cuts arent spot on but even so the pieces dont look as though they'll line up at all.. those middle two will line up with each other, but as you can see they really dont line up with the others.. are these bits too small to make fit or is it the shape of the trim im using or somesuch? thanks..

 

[kaseryn]

Btw i am using a manual mitre saw

Looking closer i see it's just the internal corners that dont seem to match.. is that because of the shape of the beading.. would a simple angle fillet match better? I could get around those frames with 2x22.5 degree cuts.. that'd minimise the internals abit... ? Would be better if i can have it all line up really

 

[kaseryn]

Hmn..i'm realising how much a mil means in this game.. seen the other thread on mitres now and with all the variation in vertices it seems to be a case of jiggerypokery. Saving all me cuts and having lots of bits a mill or so apart and finding the best fits.. then evening out for the best line on profile [i'm painting anyway so can fill the back]..

 

[big-all]

from where i am looking from all your bits are a mm or two short

take a flat edge along the main wall measure between the back and the
first step then the second step and i recon you'll be a few mm short
as in say the distance between the first space is 35mm i recon the face
off your cut will be 2mm less'ish and the same on the next step

its not just a case of measuring up to the corner you need to measure
beyond the corner to the point where the back [or faces ]off the skirting meet[intersect]

your walls could also be out as could your saw

cut a plain bit off wood at 45% rejoin the bits at 90% and see how
accurate the join when laid flat on a table

 

[kaseryn]

Hi m8 yeah that first one was v rough and well out as u say. I measured to a better line afterwards much as u describe which helps, even then though you really notice diffs in the plumb etc, and there seems to be quite a bit of play in the mitre saw, bit of an art using the thing it seems. The angles are pretty good though.. put together on a table it lines up quite well now.. but to even the joins from one wall through all the steps to the next requires something of an averaging out of the variations leaving small gaps that i can fill after.. cheers!

 

[big-all]

ok the idea of cutting a plain bit off wood is you can check the saw is
cutting square if the saw is out [twisted out of line frame] you wont get a good fit
without putting the frame right

your individual walls can be off line as well this can be on 2 planes as well
[horizontal and vertical] this would mean you need to "tinker with the
joints to get a good fit

in your instance it may be easier to match the skirting at the mitres and if
that means a mm or two gap between skirting and wall just fill and treat
as part of the skirting

 

[kaseryn]

Oh i see what you mean about checking with a plain piece. I think my biggest foulers at the moment are the variations in all the planes.. and imperfections. Quite a lot of warped and twisted timbers to negotiate. one side of a door frame has such a bulge in the middle i'm having to step out abt 5mm to keep square.. add bits and bobs of paint and dirt and its amazing how the effect seems magnified. As you say though, given i'll be paiting anyway i can play around with it quite a bit.. mainly i'm trying to keep good lines without opening mitres up as far as poss, so nothing will be noticeable when filled in. Thanks for the tips Btw..is it right that:

whatever the profile of a timber/moulding u cut, as long both cuts are the same angle, it should match? Or can you have different angles, but they would still match as long as both were lpumb?

 

[big-all]

the angle must be the same to be identical if one angle is say 40 and the other is 50
the face of the 40% will be larger and more discrepancy in angle the greater the
difference and the more pronounced the bumps and grooves

 

[kaseryn]

I see, thanks for clearing that up!

 

[TonyJover]

Coming in late here (I've only just stumbled onto this site) but bearing in mind these trims are going to be painted I'd suggest a completely different approach - scribing the corners.

Looking at your picture, and numbering the pieces from the right, I'd fix No2 first, then offer No1 up to it and mark the back face. Cut neatly with a jigsaw and apply. Then fit No4, then scribe No3 firstly against No2 and then against No4

Hope that makes sense - but you've probably done the job now anyway

Cheers,
Tone

 

[kaseryn]

Hi m8,yep its all done now but i did realise afterwards it could all have been scribed like u say.. something to remember if i ever do something like it again, but it turned out well in the end. The cheapo mitre saw i used wasnt as plumb as i thought which probably accounted for some gaps but i filled where needed and will paint when i workup the interest!