How well do you cope?

[Scrit]

I'm working on a job where I'm faced with the task of installing 5in solid timber cornice mouldings at the top of a built-up frieze hard up against the ceiling. This will mean a fair few scribed (coped) joints which I'm really looking forward to It leads me to ask if anyone has a better method of doing these other than cutting a mitre at 45º (actually as this is a 38/52º spring angle moulding the material is cut flat on the SCMS with a mitre angle of 31.6º and a mitre angle of 33.9º) then hacking away with the coping saw and wood files........ Has anyone tried the Collins Coping Foot on a jigsaw or has anyone an alternative suggestion to ease my pain

Scrit

[gazza]

Hi Scrit,
Havn't tried the Colins foot myself but i do use the jigsaw turned upside down.
I sure you know, mark the edge with a pencil then clamp in a workmate (or similar). this gives you two free hands to control the jigsaw, with a fine thin blade for cutting tight curves.
I find that it works quite well, can be very accurate, and is alot quicker than a coping saw.
HTH
Cheers,
Gazza.

[mrgrimsdale]

I'd ignore the compound angles by making up a mitre box with stops so that you just drop the stuff in and cut at 45deg. Then under-cut and take off the final adjustments with block plane, rasps, files etc. Surform is good. Also undercut the top and bottom edges of the cornice so that you can swivel it or trim a bit - but not to trim near the end or you have to trim the next bit too.
I've never done this for a cornice but I have done some complicated 3 part skirting mouldings which went around a room but also around 8no 2" pilasters - lotsa short bits with scribe at one end and mitre at the other. All good fun - and putty in the gaps.
Also you need a comfortable working height with scaffold boards. trestles etc as necessary - and a plasterboarders telescopic prop or 2 - brilliant bit of kit.

cheers
Jacob
PS forgot to say - I'd do it entirely by hand - can't see how a machine would help except for faster rough cutting.

[gazza]

mrgrimsdale said:

and putty in the gaps.

Ahh Perfection !!! ;D ;D
Cheers,
Gazza.

[jfc]

Under cutting is the key to scribing joints but i'm sure you know that . Maybe try cutting two internal mitres on some scrap and see if they will fit before you start the scribing thing .

[Scrit]

mrgrimsdale said:

I'd ignore the compound angles by making up a mitre box with stops so that you just drop the stuff in and cut at 45deg.

Not this stuff you wouldn't. It has a spring angle of 38/52º degrees as opposed to 45º. But I see your point. The problem comes with big stuff that the blasted saw just won't pass over it.

mrgrimsdale said:

All good fun - and putty in the gaps.

On oak? I think they'd possibly shoot me!

mrgrimsdale said:

Also you need a comfortable working height with scaffold boards, trestles etc

I was trying to find one of those today. It really isn't much fun trying the mitre the edge of a panel which has already been installed 10 feet above floor level.......

One thing I've already figured out is the need for an adjustable box to hold the work inverted but at the finished angle (if that makes sense) whilst I attack it with the carving tools or whatever - preferably two handed

mrgrimsdale said:

I'd do it entirely by hand - can't see how a machine would help except for faster rough cutting.

That's what I'm trying to do - find a way to do the rough cutting in 5 to 6 minutes rather than 15 to 25......

jfc said:

Under cutting is the key to scribing joints but I'm sure you know that .

Yes - but I still dislike using a jigsaw inverted.

jfc said:

Maybe try cutting two internal mitres on some scrap and see if they will fit before you start the scribing thing .

That's necessary as not all profiles will scribe, and in any case the starting point for a complex moulding scribe is a mitre cut (in this case in the "correct" direction, however, I'm not happy at the thought of mitring 3 metre long lengths at their ends. Something tells me that over time they'll open up whereas a scribed joint if it opens up will be somewhat less obvious

Scrit

[jfc]

Erm , how is a mitre going to open up any more than a scribe ? If anything it's better as you have more glue surface .

[Sgian Dubh]

scrit said:

This will mean a fair few scribed (coped) joints--- It leads me to ask if anyone has a better method of doing these other than cutting a mitre at 45º --- then hacking away with the coping saw and wood files-- Scrit

Cut the 45º on the one end of the cornice moulding as required for the internal corner. Then an angle grinder and Arbortech attachment has always worked well and very quickly for me to 'refine' the back cut.

In the end, it's 'up tight and outta sight' as they say, so if the back cutting is a bit rough, who's going to see it anyway? Slainte.

[dom]

Welcome SD, really good to see you here.

Dom

[mikew]

jfc said:

Erm , how is a mitre going to open up any more than a scribe ? If anything it's better as you have more glue surface .

Because a miter will open from both halves of the stock. A coped joint done well only one-half of the stock visually moves (both do, but the butted piece is immaterial).

fwiw, on coped inside corners of moulding that would not fit the SCMS, I made the U-shaped miter boxes from scrap that the inside would hold the stock at the spring angle and hand cut them. Then coped inside joins. Right on the scaffold to avoid going up and down.

Take care, Mike

[mrgrimsdale]

mikew said:

snip
fwiw, on coped inside corners of moulding that would not fit the SCMS, I made the U-shaped miter boxes from scrap that the inside would hold the stock at the spring angle and hand cut them. Then coped inside joins. Right on the scaffold to avoid going up and down.

Take care, Mike

Thats what I was saying more or less except it'd be an L shaped mitre guide with just a stop in place of the near side of the box (nails, or a lath) and the line to be cut marked up with a pencil - and followed by eye. Can also be marked on the face of the cornice by laying on a straight edge and eyeing a pencil line down it.

cheers
Jacob

[paulchapman]

Hi Richard,

Welcome - great to have your expertise here

Cheers

Paul

[Sgian Dubh]

Thanks Dom and Paul. I've been lurking for perhaps three or four weeks, in particular to see just how forthright, aggresive and dismissive of 'the new' Jacob might be in an unfettered environment. So far I haven't been disappointed, ha, ha-- ha, ha, ha. Slainte.

[mrgrimsdale]

sgiandubh said:

Thanks Dom and Paul. I've been lurking for perhaps three or four weeks, in particular to see just how forthright, aggresive and dismissive of 'the new' Jacob might be in an unfettered environment. So far I haven't been disappointed, ha, ha-- ha, ha, ha. Slainte.

Not quite sure how to interpret that. What have I said, I wonder?
Could this be seen as the first example of "personal attack" on the forum so far, or am I being over-sensitive?
It's much more civilised to stick to issues IMHO.
I'm not so much dismissive of "the new" as defensive of "the old" as I'm quite convinced that modern woodworkers are endlessly trying to re-invent the wheel with new solutions to problems long ago solved.

cheers
Jacob

[Alf]

jfc said:

Erm , how is a mitre going to open up any more than a scribe ? If anything it's better as you have more glue surface .

End grain glue surface...?

Welcome, Richard. Go on, Jacob, report him. ;D

Cheers, Alf

[jfc]

Long grain shrinkage ...?

[dom]

What the hell has rice got to do with it ;D

[Sgian Dubh]

mrgrimsdale said:

Not quite sure how to interpret that. What have I said, I wonder?
... am I being over-sensitive? Jacob

mrgrimsdale said:

...more and more dubious about the info produced by highly respected "experts" ...wonder if it's all a plot to confuse... and keep the craft mysterious and protected Or do they just make it up as they go along to keep ahead of the class, in the traditional teachers way ;D

Yes, you are being overly sensitive Jacob, but I did notice your comments above in another thread, and wondered what you could possibly mean, notwithstanding the emoticons slipped in here and there to indicate you were joshing.

After all, as someone that both teaches furniture making, and gets paid to write on the subject, I can hardly think of a worse way to go about the job than 'making it up as I go along.' I rather hope that I teach and write about furniture making subjects with authority based on the premise that I've probably forgotten more about it than most people learn in a lifetime. Slainte.

[mrgrimsdale]

toobyefore said:

jfc said:

Erm , how is a mitre going to open up any more than a scribe ? If anything it's better as you have more glue surface .

End grain glue surface...?

Welcome, Richard. Go on, Jacob, report him. ;D

Cheers, Alf

Mitre shrinks both sides, scribe one side only so half the gap. Also on a scribe the un cut piece goes through and visually closes the gap, which will tend to be in a shadowy corner and less noticeable. So the mitres need to be neater and better fixed than the scribes. Mitre usually has a nail or 2 through the corner as well as glue.

cheers
Jacob

[mrgrimsdale]

sgiandubh said:

mrgrimsdale said:

Not quite sure how to interpret that. What have I said, I wonder?
... am I being over-sensitive? Jacob

mrgrimsdale said:

...more and more dubious about the info produced by highly respected "experts" ...wonder if it's all a plot to confuse... and keep the craft mysterious and protected Or do they just make it up as they go along to keep ahead of the class, in the traditional teachers way ;D

Yes, you are being overly sensitive Jacob, but I did notice your comments above in another thread, and wondered what you could possibly mean, notwithstanding the emoticons slipped in here and there to indicate you were joshing.

After all, as someone that both teaches furniture making, and gets paid to write on the subject, I can hardly think of a worse way to go about the job than 'making it up as I go along.' I rather hope that I teach and write about furniture making subjects with authority based on the premise that I've probably forgotten more about it than most people learn in a lifetime. Slainte.

I thought it was fairly obvious what I meant in that thread and it certainly wasn't meant to include everything written by all media experts/teachers all the time so you shouldn't take it personally especially as I've always thought your stuff was spot on.
As it happens I've been reading a good deal lately, based partly on recommendations picked up in _{other groups} - a lot of interesting things which I knew little about but also some very doubtful stuff put forward, not to mention the dodgy practice of product placement esp in the mags - where many reviews and articles can't be trusted. A dose of sceptiscm can be a good thing now and then, and it amuses me even if it does occasionally annoy others ;D

cheers
Jacob

[Alf]

Jacob, just for once that's something I know - simply surprised that Jason was thinking an all end-grain gluing surface was some, indeed any, benefit. Which could be why I don't go round thinking "pro" equals "knows it all" and will continue to annoy y'all in consequence...

Cheers, Alf

[jfc]

I did'nt say i knew it all , in fact i think you learn untill the day you die . So do tell Alf , why is glueing a mitre pointless when it is normal practice ?

The point i was trying to make is that if a mitre fits then why bother doing a scribe joint . If it doesnt then it's probably quicker to do a scribe joint than mess around with two large timbers above your head .

[dom]

Have I got it all wrong or could you not do this with the chop saw set at a compound angle and the coving set at 45 degrees..

Dom

[Alf]

Oh hell's bells, don't you start taking offence as well, Jason, please. I don't know why gluing mitres is standard practice - the triumph of hope over experience? The difference between man-made stuff and solid wood?

Cheers, Alf

[jfc]

Im not offended i just wondered why you questioned glue on end grain when it is a standard practice to glue a mitre internal or external . Also i wonder why people are saying dont mitre the internals when the externals have to be mitred and will show more of a gap than an internal .