On 08/10/2020 20:15, wrote:
On Thursday, 8 October 2020 19:35:24 UTC+1, williamwright wrote:
On 07/10/2020 16:51, Tricky Dicky wrote:
To cut the Celotex floor insulation into joist gap panels, I bought some of these jigsaw blades which should be good for up to 100mm.

https://www.amazon.co.uk/Bosch-Profe.../dp/B000R5LTGC

Now the jigsaw is not one of my favourite tools so I have never owned an expensive one due to the little use I make of it. What I am finding is go slightly off line and the blade bends out and it is almost impossible to get a perpendicular cut over 1.2m in 75mm Celotex. Some of the reviews mentioned this and I was wondering if the problem is down to the blade having no set therefore not cutting a proper kerf or is it down to the jigsaw?

Richard

Try steering the jigsaw by rotating it slightly in the vertical axis and
always only applying force in the exact direction the blade is aligned
to. Don't apply any sideways force, which you might be doing instinctively.

Bill

Or do yourself a bigger favour & don't use a jigsaw.


NT


I have used those bosch blades for cutting 70mm quinntherm
and they worked fine for me.

Another method is to turn the back edge of a hacksaw blade
into a sharp knife and make a handle for it. By pulling
through the 'celotex' at 45 degrees an accurate cut is
easy.

For 50mm celotex a stanley knife with a longer blade is
perfect for a clean cut.