PDA

View Full Version : cutting foam sandwich



DoubleChevron
12th April 2024, 09:02 AM
Hi Guys,

I have some old (well new caravan walls) that my brother left laying in the paddock down here about 5 years ago. I'm thinking of building a home office with them. They are 40mm caravan walls. thin fiberglass with high density foam. Does anyone know and effective way to cut theses for doors/windows? I'm thinking a high tooth count saw blade of some sort .... possibly :)

I do not bunnings has cheap ozito track saws for sale cheaply. I wonder how these would go .... :unsure:

seeya
Shane L.

Killer
12th April 2024, 11:20 AM
Cutting with a router would be the best way to avoid chipping the outer skin. This is how the manufacturers do it. If you use a circular saw you may have success by using a sacrificial board between the sheet and the machine to give the outer skin support when the saw tooth breaks through.

DoubleChevron
12th April 2024, 01:12 PM
Cutting with a router would be the best way to avoid chipping the outer skin. This is how the manufacturers do it. If you use a circular saw you may have success by using a sacrificial board between the sheet and the machine to give the outer skin support when the saw tooth breaks through.

A router .... Now that is something I would never have thought to use. Thanks! I'll give it a try :)

Max Headroom 2.3m
12th April 2024, 01:33 PM
Ordinary steel blade will dull quickly on fibreglass and will chip, even fine toothed blades. Diamond wheel for an angle grinder cuts fibreglass nicely with no chips and the foam should be no problem. I'd cut from both sides instead of doing it in one and drill the corners to transfer reference. If money is no object, get a diamond wheel for a circular saw. You can also get diamond edged blades for reciprocating saws if you want to cut from one side. Just take it easy and should not chip.

DoubleChevron
12th April 2024, 03:08 PM
Ordinary steel blade will dull quickly on fibreglass and will chip, even fine toothed blades. Diamond wheel for an angle grinder cuts fibreglass nicely with no chips and the foam should be no problem. I'd cut from both sides instead of doing it in one and drill the corners to transfer reference. If money is no object, get a diamond wheel for a circular saw. You can also get diamond edged blades for reciprocating saws if you want to cut from one side. Just take it easy and should not chip.

Hmmm... I've always wanted to try one of those diamond saw blades ... :)

Blknight.aus
12th April 2024, 03:19 PM
the diamond saw blades work well.

use a cordless grinder keep it in a bag and keep the work wet.

as per other comments, corner drill, line mark, all the other good cutting thick stuff info.

AND..

use the double glaze windows if you can get them, or use 2 outer window shells and do your own double glaze.

If you dont,, get the windows with the screen adjacent to the window then you can use the bottom edge as a shelf for pen organizers and the like... (depending on where you put your windows)

Dont forget to get some good sealer on the foam before you put the windows in. Keeps bugs, rodents and moisture at bay.

DoubleChevron
12th April 2024, 08:04 PM
the diamond saw blades work well.

use a cordless grinder keep it in a bag and keep the work wet.

as per other comments, corner drill, line mark, all the other good cutting thick stuff info.

AND..

use the double glaze windows if you can get them, or use 2 outer window shells and do your own double glaze.

If you dont,, get the windows with the screen adjacent to the window then you can use the bottom edge as a shelf for pen organizers and the like... (depending on where you put your windows)

Dont forget to get some good sealer on the foam before you put the windows in. Keeps bugs, rodents and moisture at bay.

Amazing, yes I have a crappy ozito cordless grinder here (they are quite gutless.... but very safe due to this). So I'll grab a diamond blade and see how I go!

DoubleChevron
31st May 2024, 09:39 AM
Amazing, yes I have a crappy ozito cordless grinder here (they are quite gutless.... but very safe due to this). So I'll grab a diamond blade and see how I go!

thanks for that suggestion ... that did work. I just grabbed a diamond blade for my 5" 240v grinder.

190275

this is that cheap 50x50x2 rhs on fb marketplace. apparently its cheap as it comes from shipping container shelving.




190276


190277

190278

190279

190280

don't you love how square everything is [bigrolf]

190281

I just ran masking tape where I wanted the cuts and drilled the corners. and cut one side out, then turned it over and cut the same spots on the other side but following the holes drilled thorugh as a guide.