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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Carpentry Questions >> COVING ON A MITRE SAW. https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1084714016 Message started by Dusty on May 16^th, 2004, 2:26pm

Title: COVING ON A MITRE SAW.
Post by Dusty on May 16^th, 2004, 2:26pm

;D :)Like many others I have a power mitre saw. Great bit of kit, cuts timber at an angle and tilts. It also cuts plaster coving beautifully.

Can�t quite seem to get the combination of angle and tilt quite right. Does anyone know the angles to use to set it up, to cut coving when its laid flat on the mitre bed?

Thanks Dusty.
:) :) :)

Title: Re: COVING ON A MITRE SAW.
Post by big_all on May 16^th, 2004, 2:30pm

helllooo dusty

this was coverd yesterday
ill look for it ??? ???

its under funny enough

mitres on cornises ::) ::)

Title: Re: COVING ON A MITRE SAW.
Post by Dewy on May 16^th, 2004, 4:08pm

Here you go Dusty. This was asked on the trade forum.

wrote on May 14^th, 2004, 12:34am:

Simple!!!!!!!!!!!!!!!
the answer to the question of a wide cornice, laid flat, what angles to cut at is as follows......

the vertical angle for a 45/45 cut is 35.3 degs and the horizontal angle is 30 degs
basic trigonmetry dear fellows.... call your selves chippies.... OOOOOOOOOOOOPPPPPPPSSSS! sorry forgot, they have not taught trig at schools/colleges for a bloody long time... god am i showing my age or what...!!!!!
which is why you will find on the real quality powered and non-powered mitrew saws the following angles... 31.6/33.9 and of course 35.3 degrees.....
now you lot know!!!!!
regards the over worked matt :o :o :o :o :o :o :o :o

Thanks go to WOLF for the answer. :D

Title: Re: COVING ON A MITRE SAW.
Post by Windy Miller on May 16^th, 2004, 9:15pm

Mire saws are great for cutting coving, but remember to brush away the plaster 'sawdust' from the saw, as it sets hard in no time and it's a bugger to get off!
Windy

Title: Re: COVING ON A MITRE SAW.
Post by Dusty on May 17^th, 2004, 9:42am

:) :)Thanks guys, most helpful. :) :)

::) ::) ::) ::) ::)
There should be a section on this forum for data like this so people like me don't keep asking the same question.

Title: Re: COVING ON A MITRE SAW.
Post by garyclay on Oct 26^th, 2004, 8:36pm

If the corners aren't 90 degrees, and they usually are not I use the table from this site that I printed out. Have a look at

http://www.dewalt.com/us/articles/article.asp?Site=woodworking&ID=2

Table is at the bottom of the page. Useful pics too. No doubt all you pros knew this but for DIY numpties like me it was a life saver!!!

Title: Re: COVING ON A MITRE SAW.
Post by woodsmith on Oct 26^th, 2004, 9:50pm

Thanks for that link Gary and welcome to the forum.

There is a formula for working this out, but the chart looks a lot easier to use.

Keith

Title: Re: COVING ON A MITRE SAW.
Post by Dewy on Oct 26^th, 2004, 10:30pm

Those charts remind me of my youth when learning my trade.
A great part of our work was producing angles, either by stepping them using tangents or tilting the cutter.
Very often the cutter had to be tilted at an angle instead of square to the datum line.
I asked everyone if there was a way to calculate this angle to produce the required one in a different plane and non of the skilled men, foremen or draughtsmen knew.
I got hold of a book of tables and worked the angle out the long way and realised that one of the steps gave the natural secant of the angle.
I soon had a formiula that I used for finding any angle needed from whatever point I approached the job from and marked every finished angle in a notebook that became my bible.
Others plus the management regualarly asked me how I managed to work so accurately and my only reply was "I calculated the angles"
Noone ever did see my 'bible' or if they did they had no idea what all the figures were for. lol

The formula was the same as needed to produce the figures used on that DeWalt site.

A cotangent multiplied by the reciprocal of another cotangent to find the cotan of a cosine was not my idea of fun. ???

Title: Re: COVING ON A MITRE SAW.
Post by JerryD on Oct 26^th, 2004, 10:38pm

wrote on Oct 26^th, 2004, 10:30pm:

A cotangent multiplied by the reciprocal of another cotangent to find the cotan of a cosine was not my idea of fun. �???

I had one of them, but the wheels fell off ??? ??? ???

Title: Re: COVING ON A MITRE SAW.
Post by Kesh on Oct 27^th, 2004, 11:48pm

He he, you could aways do it by "eye" - What do you think they invented "polyfilla" for!;)

Title: Re: COVING ON A MITRE SAW.
Post by big_all on Oct 28^th, 2004, 12:47am

you lazy bu66er you are supposed to do it 95% then use filler :D :D

Title: Re: COVING ON A MITRE SAW.
Post by Dewy on Oct 28^th, 2004, 12:53am

I just KNEW I was doing something wrong.
I thought it was 5% wood with 95% polyfilla. ;)

Title: Re: COVING ON A MITRE SAW.
Post by big_all on Oct 28^th, 2004, 1:18am

well as you know filler in good woodwork is not allowed[less than 1%]but in the real world 2 or 3 %[5%at a push]is ok ;)

Title: Re: COVING ON A MITRE SAW.
Post by splinter on Oct 29^th, 2004, 11:31pm

wrote on Oct 26^th, 2004, 8:36pm:

What is the idea of the 52/38 degree crown moulding mitre cut :)

Title: Re: COVING ON A MITRE SAW.
Post by Dewy on Oct 29^th, 2004, 11:42pm

The angles on the chart are what you set the mitre saw to when laying the moulding flat on the table

Title: Re: COVING ON A MITRE SAW.
Post by jasonB on Oct 30^th, 2004, 8:12am

splinter, 52/38 deg refers to a crown moulding where one leg, usually the bottom is longer than the other unlike regular cove which has equal legs.

If you drew an imaginary line through where the ends of the moulding meet the wall it would form a triangle 52/90/38 as opposed to 45/90/45.

Jason

Title: Re: COVING ON A MITRE SAW.
Post by garyclay on Oct 30^th, 2004, 8:54am

The 52/38 refers to a type of moulding that doesn't sit at 45 degrees to the wall and ceiling. 52/38 is what is known as the spring angle. With these mouldings they sit lower on the wall and less on the ceiling, or vice versa.

These are less common in the uk at the moment.

Find out more about spring angles and get a load more coving tips at another cracking site I found

http://www.altereagle.com/How_to_install.html

Hope that helps.

Title: Re: COVING ON A MITRE SAW.
Post by splinter on Oct 30^th, 2004, 4:20pm

Jason&garyclay,
� � � � � � � � � � � Thanks for the reply,simple really,now I know. Good clear concise anwsers .
.�like big-all says we always learning
ps I found the web site very helpful. :)