birds mouth cut

[kingcod]

beginners question:

how should I attempt to make a shallow angled cut in a 100 mm square rafter? The roof angle for my woodstore means that neither my hand held circular saw nor table saw can handle it. Nerther go beyond 45 degree. I don't have a band saw and its beyond the reach of a jig saw. I am currently struggling with a chisel and plane to approximate the cut .. and there are 5 rafters!



Image dimensions are exaggerated to show the angle.

 

[TrimTheKing]

Erm, is it too obvious to suggest a handsaw?

If you are worried about your sawing then draw out your marking lines, cut inside them then pare away the waste with a chisel.

 

[Chems]

I had to chuckle at this one.

A saw man! A hand saw!

Also you can do an over 45 degree cut with your table saw by adding some wedges to your workpiece to increase the angle. Lots of work for something that can be done by hand in minutes.

 

[studders]

Well, if for some reason you can't use a handsaw then a jigsaw would do it.

 

[Chems]

He said that his jigsaw couldn't handle it.

 

[studders]

He said that his jigsaw couldn't handle it.

Didn't read it proper.

 

[MikeG.]

I have never seen them done any other way other than with a handsaw. Cut from both sides. I can't imagine why Kingcod would have tried anything other than a handsaw.

Make one "pattern piece", mark it boldly, and use it to mark up all the others. I have seen someone make a piece and then use it to mark up the next piece, then use that one to mark up the following one etc......by about the 5th rafter the cumulative errors made the rafter un-useable.

Mike

 

[chippy1970]

He said that his jigsaw couldn't handle it.

I cant see why he says a jigsaw wont do it, maybe he has a mickey mouse jigsaw. I quiet often cut mine with a jigsaw when in a hurry, you get the odd "rough bugger" comment but it all depends how good/confident you are with a jigsaw.

At the end of the day a handsaw is the best tool for the job if you want them nice and square.

 

[MikeG.]

if you want them nice and square.

Yes please!

Mike

 

[xy mosian]

Use a hand saw. Start the cut square to the surface only about 2mm deep but all the way across. That will give a nice groove for the saw to start in when starting at the correct angle. Otherwise the saw has a tendency to slide down the surface of the timber instead of getting a good start. Don't rush the cut.


xy

 

[studders]

How about a finely tuned Axe?












No? OK then. :lol:

 

[hog&bodge]

I suggest you train a beaver. I have varied results with this method
& when it comes to sharpening its teeth you will find it is a very
ungrateful little critter..Makes me wish I had just used a saw

 

[Mcluma]

I had to do over 30 rafters and i did them with the jig saw

 

[Sgian Dubh]

I cant see why he says a jigsaw wont do it...

He did say the material is 100 mm (4") square didn't he? Maybe that's the reason as most jigsaws and their blades won't cut that deep.

It's a five minute job with a handsaw, as many others have pointed out. Slainte.

 

[jasonB]

I have never seen them done any other way other than with a handsaw. Cut from both sides. I can't imagine why Kingcod would have tried anything other than a handsaw

If the pitch is around 45deg then it is possible to clamp all the rafters together with the birdsmouth facing up, set your saw to the angle and cut the whole lot in one pass, then do the second cut from the other side. This will not work on this roof as the circ saw will not tilt to 60deg but you could do the 30deg cut that way.

But as has been said as there are only 5 rafters its quicker by hand.

Jason

 

[chippy1970]

I cant see why he says a jigsaw wont do it...

He did say the material is 100 mm (4") square didn't he? Maybe that's the reason as most jigsaws and their blades won't cut that deep.

It's a five minute job with a handsaw, as many others have pointed out. Slainte.

Yeah I missed that I suppose it would be a bit too much even though Bosch ones go upto 135mm in depth of cut.

 

[Mr Ed]

This is what you need;

or you could use a £5 handsaw as suggested...

Ed

 

[kingcod]

Thanks for all your helpful advice. Handsaw it is then - I think I had got so obsessed with powertools that I forgot how my dad used to do such things! time to relearn some old fashioned skills.

The Jigsaw 'Puzzle' (see what I did there?) - with 100mm depth its too much.

I love the beaver solution.

Will report back!

 

[milkman]

you could line the rafters up and ‘gang-cut’ a series of parallel kerfs to the required depths. knock out the cuts and clean up with a slick or a plane. Cant see this would be much more of a pain than handsawing

 

[Russell]

Saw a workman in the street doing a extension just up the road cutting birds mouths with a hand held circular saw held in one hand with the rafter balanced on a wall and a pile of bricks, standing with one foot on the work piece to hold it down and a his other hand the other side of the saw. Crazy