Cutting foam

[Blobber]

Every harvest i keep thinking I must do something with the tractor seat, once youve been it for a while it really isnt comfy and the pink yoga matt was a temporary thing as I didnt have a lot of use for it! I managed to find a nice chunk of 4 inch foam which will need shaping so anyone got any good ideas on tools to use?

 

[Cato]

I don't know what the right/approved way is, but a mate of mine made a custom shaped motorbike seat (cut down base, different shape faom etc). He used an electric carving knife and it worked really well.

 

[Nomad]

I've had decent results in the past* with a long serrated knife (bread knife or carving knife), also by cutting with a hotwire (thin strand of wire stretched in a frame - similar to an olde worlde jigsaw, connected to a low power source - I think I used an old 12v transformer from a train set !)
Electric carving knife also sounds a good bet.
* It was a long time ago but as a youngster I reshaped several motorcycle seats.

Anything you use has to be sharp or you end up tearing lumps off when you shape it not the look you want

 

[The_Yellow_Ardvark]

Soft foam, sharp knife. Or Hot wire cutter.
Dense faom, bread knife.

 

[JEZGUZ]

Electric carving knife again, and hand carving knife but it has to be really sharp. I've used both methods and don't even think about a stanley type knife, it just won't work.

 

[dyno-tron]

Extra sharp carving knife or wavy edge bread knife have been good when I’ve been cutting foam

 

[awemawson]

Electric carving knife works wonders on upholstery foam


SNAP !

 

[AKN]

I did summer work in a master upholsterer’s, we used for rough quick cuts a cross cut board saw pulled backwards for the cutting stroke. For neat cuts a very sharp Kitchen Devil.

 

[James1979]

+1 (or is it + 5!!) for electric bread knife.

I’ve also made a Hotwire in a frame from an old coping saw and a couple of insulators at either end of the wire to do the seats in our camper. Controlled it off a train set control so you can turn it up and down as needed.

Do it outside. It stinks and it makes you feel ill

 

[Blobber]

Electric carving knife it is then! think we have one of those in that kitchen thing somewhere, thanks for the input!

 

[keithski122]

I do car upholstery and have a very expensive bosch foam cutter, its a bit like a jigsaw with two 12 inch blades next to each other.However an electric carving knife works well. You could use a bandsaw for the sides.
Here's a good tip which not many people know of is that a spice grater makes a great sander for shaping foam.

 

[Windy Miller]

I remember the bloke at the foam stall in Gravesend Market using an electric carving knife. Seems to be the way to go!

 

[jsf55]

My make do is a kitchen bread knife and pledge polish on the blade to slip through it easily, also wash knife afterwards

 

[500e]

As @jsf55 a bit of lube works wonders

 

[DAPPH]

Buy a pot of in date expanding foam resin for about 10 litres of hard foam , mix it then put in a strong poly bag on the bare seat then after a few seconds just before it sets sit on the bag so it take up your butt profile , empty your back pockets first so you don't get an iphone imprint etc . ( racing cars seats inserts are made like this ) . Then do the soft foam lining adding numerous skin breathing holes in the foam & the foam sheet . Maybe a final covering of cotton canvas to help keep your butt & nuts cool .

Just remember to cover it over when not in use to keep it clean & rain out

 

[graffian]

I don't know what the right/approved way is, but a mate of mine made a custom shaped motorbike seat (cut down base, different shape faom etc). He used an electric carving knife and it worked really well.

The trimmer who did a seat for me used an electric carving knife for rough cuts, a ham knife to finish the shaping and then he
went over it with a power file. When he was happy with it he put a bit of thin foam over it.

The result was a lovely job and it was very easy to do, yes it was I watched him;-)

 

[Turbo]

A hacksaw blade also works quite well.

 

[Screwdriver]

Easy to build, cheap, perfect results. Bit of an overkill for one job but you could jury rig something like that in minutes. All you need is some nichrome wire.

 

[hunter27]

Buy a pot of in date expanding foam resin for about 10 litres of hard foam , mix it then put in a strong poly bag on the bare seat then after a few seconds just before it sets sit on the bag so it take up your butt profile ,

Good idea but I hope you are better with expanding foam than me, no matter how much I prepare for the job I end up with it on something it shouldn't be on. We had a full can of foam in a bucket with some tools tools and it got punctured on a sharp edge, still got foam on some of the tools 8 years later

 

[pedrobedro]

Electric carving knife again, and hand carving knife but it has to be really sharp. I've used both methods and don't even think about a stanley type knife, it just won't work.

I use a snap off type blade fully extended it cuts most types of foam cleanly. Particle foam is good for seat beds and you can cut it easily with anything sharp.