cutting irregular shape plywood

[Zaffy]

I need to replace the underside of a soffit. The length narrows in width as it goes along. Is measuring the width every few centimetres the only way to cut it accurately? Should I make a cardboard template first? Cutting the board smaller and filling gap with silicone is what I am trying to avoid. Thank you

 

[graduate_owner]

I would be interested in any comments here. My soffites butt up against a very irregular stone wall and there are so many gaps. We get birds nesting there quite often. I was hoping to avoid copious volumss of foam.

K

 

[furrydude]

Hi
My suggestion would be to scribe it in. Support the board (however you can safely), a set gap from the wall/edge, then use a spacer the same size as the gap, attach a pencil and run it along the wall; this should give you line to which you can cut and should, perhaps with a little fettling, fit nicely. If going around the stone and into the joint, use a spacer with a pointed end (hope that makes sense).

Clearly, all the usual stuff about working at hight safely apply...

Regards

 

[Adam9453]

If its a straight forward consistent taper, i.e. both sides are straight but they taper towards each other then measure each end and connect the dots.
If however they are not straight then scribe it in.
If you are not confident with scribing then make a cardboard template and practise scribing the template in first.
Once you have done it a few times you will get an acceptable result I expect.
Its not difficult but it does take a degree of care and patience to get a nice close match.
Also don't put yourself under immense pressure to get it within 0.5mm all the way along, its a soffit so a little tolerance will be perfectly acceptable.