smileygirl
New member
I need to cut a foam mattress down from a double , into two singles plus an infill. whats the best way to cut foam and get a reasonable finish ????
cutting foam
- Thread starter smileygirl
- Start date
saltwater_gypsy
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- Joined
- 13 Jan 2008
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- Now back in Scotland . Boat for sale
Skill with a saw or bread knife or the right blade in a jigsaw.
argus
New member
Use an electric carving knife lubricate (not essential) with ptfe spray, clean before carving the Sunday roast.
I did it, converting a 3" thick super king size memory foam topper (Ebay) into two triangular-ish shapes for the fore cabin and 4 pillows.
Peter
I did it, converting a 3" thick super king size memory foam topper (Ebay) into two triangular-ish shapes for the fore cabin and 4 pillows.
Peter
Refueler
Well-known member
[ QUOTE ]
I need to cut a foam mattress down from a double , into two singles plus an infill. whats the best way to cut foam and get a reasonable finish ????
[/ QUOTE ]
Hot wire cutting is the only way to get a straight uniform cut. Forget kinves etc. as they will end up with uneven and horrible cut.
So where do you get the wire ? How do you mount it ? What power to use ?
Nichrome wire from an electric fire element. Extract the whole wire length from a 1kw element. Now form a strong small loop in one end and fix to the wall ... make locking loop round a bar at other end and 'lean-back' putting strain on it to straighten it out.
Now going back to childhood days make a Robin Hood style long-bow with the wire as the 'string'. When fixing to the bow ends ... make sure you have a tail for connecting power wires to. Run two core cable onto the bow frame ... split and lead one to one end .. other to other ... connect and leave cord as flex to connect to power. Make sure bow can be handled without you touching wire - it gets HOT !!
Now a standard 1kw length of wire will be well powered by a 12v source such as a battery and if via a model railway variable controller - you can alter heat to suit material.
It works and is a doddle for cutting polystyrene, foam mattress, all sorts of that style. It doesn't back-fill with molten foam if done well. The cut is sealed and if you do not force - then straight and even.
I used to cut model airplane foam wings with above along with friends divan foams etc.
Once you use one - you'll never waste time with knifes again !! But it does smell when cutting - so well ventilated room or outside as some of the foam vapours are toxic in confined spaces.
I need to cut a foam mattress down from a double , into two singles plus an infill. whats the best way to cut foam and get a reasonable finish ????
[/ QUOTE ]
Hot wire cutting is the only way to get a straight uniform cut. Forget kinves etc. as they will end up with uneven and horrible cut.
So where do you get the wire ? How do you mount it ? What power to use ?
Nichrome wire from an electric fire element. Extract the whole wire length from a 1kw element. Now form a strong small loop in one end and fix to the wall ... make locking loop round a bar at other end and 'lean-back' putting strain on it to straighten it out.
Now going back to childhood days make a Robin Hood style long-bow with the wire as the 'string'. When fixing to the bow ends ... make sure you have a tail for connecting power wires to. Run two core cable onto the bow frame ... split and lead one to one end .. other to other ... connect and leave cord as flex to connect to power. Make sure bow can be handled without you touching wire - it gets HOT !!
Now a standard 1kw length of wire will be well powered by a 12v source such as a battery and if via a model railway variable controller - you can alter heat to suit material.
It works and is a doddle for cutting polystyrene, foam mattress, all sorts of that style. It doesn't back-fill with molten foam if done well. The cut is sealed and if you do not force - then straight and even.
I used to cut model airplane foam wings with above along with friends divan foams etc.
Once you use one - you'll never waste time with knifes again !! But it does smell when cutting - so well ventilated room or outside as some of the foam vapours are toxic in confined spaces.
saltwater_gypsy
New member
- Joined
- 13 Jan 2008
- Messages
- 1,946
- Location
- Now back in Scotland . Boat for sale
Wow!!
Remember to film it for You Tube. There sounds like plenty of scope for disaster with hot wires, , toxic fumes etc but good luck!!!!
Remember to film it for You Tube. There sounds like plenty of scope for disaster with hot wires, , toxic fumes etc but good luck!!!!
S
Skyva_2
Guest
The electric carving knife works very well, just used it for a bed head, cuts nice and square. It was bought for the purpose, about £15. Also slices fresh baked bread!
Quandary
Well-known member
It is particularly difficult to cut foam neatly with ordinary hand tools. If you try to compress it too much it never looks like a clean cut and it is difficult to get at the cut in a piece the size you are working with. I would use a long handsaw with medium teeth after placing the foam on a big table or a sheet of ply or similar with another about 2 feet wide on top as a straight edge. The idea is to apply even compression to the cut all the way. Keep the saw almost horizontal and go very slowly with long straight strokes, don't press down too hard.
If it a good piece of foam it might be better to get a local upholsterer to do it. If you only need one of the pieces you could do a temporary rough split and then trim the edge straight when you can get beside the cut.
Of course if it is going to be upholstered the cut may never be seen again so perfection may not be essential.
If it a good piece of foam it might be better to get a local upholsterer to do it. If you only need one of the pieces you could do a temporary rough split and then trim the edge straight when you can get beside the cut.
Of course if it is going to be upholstered the cut may never be seen again so perfection may not be essential.
VicS
Well-known member
Another vote for the electric carving knife. Cut all mine with ours. Easy to do and get near perfect results.
Hot wire's good for polystyrene foam, can give off toxic fumes from some materials, but for foam for bunk cushions electric carving knife every time!
Dont forget the foam must be a bit bigger than the cover to get a good tight fit.
Hot wire's good for polystyrene foam, can give off toxic fumes from some materials, but for foam for bunk cushions electric carving knife every time!
Dont forget the foam must be a bit bigger than the cover to get a good tight fit.
111KAB
New member
Guy on our local outdoor market (Midlands) cuts foam to size with a hot wire cutter ..... best to find similar near you if you want pristine finish.
Refueler
Well-known member
[ QUOTE ]
Guy on our local outdoor market (Midlands) cuts foam to size with a hot wire cutter ..... best to find similar near you if you want pristine finish.
[/ QUOTE ]
Thank you for that post. I'm glad someone else also knows about it.
As I said in my post describing how to make a cutter - I used one for years cutting all sorts of foams and polystyrenes. have gone into upholstery workshops and seen the vertical hot wire cutter beds ...
Oh well - try to help ... again thanks for your post ! /forums/images/graemlins/wink.gif
Guy on our local outdoor market (Midlands) cuts foam to size with a hot wire cutter ..... best to find similar near you if you want pristine finish.
[/ QUOTE ]
Thank you for that post. I'm glad someone else also knows about it.
As I said in my post describing how to make a cutter - I used one for years cutting all sorts of foams and polystyrenes. have gone into upholstery workshops and seen the vertical hot wire cutter beds ...
Oh well - try to help ... again thanks for your post ! /forums/images/graemlins/wink.gif
Refueler
Well-known member
[ QUOTE ]
Wow!!
Remember to film it for You Tube. There sounds like plenty of scope for disaster with hot wires, , toxic fumes etc but good luck!!!!
[/ QUOTE ]
Oh well - you can't please 'em all ...... some believe, some don't. Not my problem ! /forums/images/graemlins/grin.gif
Wow!!
Remember to film it for You Tube. There sounds like plenty of scope for disaster with hot wires, , toxic fumes etc but good luck!!!!
[/ QUOTE ]
Oh well - you can't please 'em all ...... some believe, some don't. Not my problem ! /forums/images/graemlins/grin.gif
nickcred
New member
Hot wire definitely best, after a summer job in my youth, normally the best way to get a perfect cut, unless it is only and 1" or 2" memory foam and I successfully cut that this weekend with a extremely sharp hunting knife and a marker pen, not for the nervous however 
DownWest
Well-known member
While the hot wire is better (yes, I've made one for aircraft bits) the electric carving knive is perfectly adequate for bunk cushins, and lots of people have them (or one's neighbours /forums/images/graemlins/grin.gif)
A
A
Strathglass
New member
I usually use a electric knife for cutting foam. Never had any problems don't compress it too much or you will get a wavey edge.
I have used a hot wire to cut polystyrene blocks. The fumes are quite bad.
My hot wire cutter was a piece of eurika resistance wire about two feet long held between two sticks of wood with heavy wires from the ends of the eurica to my old SIP140 welder turned well down.
It worked very well.
I have used a hot wire to cut polystyrene blocks. The fumes are quite bad.
My hot wire cutter was a piece of eurika resistance wire about two feet long held between two sticks of wood with heavy wires from the ends of the eurica to my old SIP140 welder turned well down.
It worked very well.
absit_omen
New member
I used a bandsaw to achieve exactly what you require.
TQA
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- Joined
- 20 Feb 2005
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- 6,815
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- Carribbean currently Grenada
WARNING
Depending on the foam the fumes can be VERY TOXIC.
Depending on the foam the fumes can be VERY TOXIC.
Ruffles
Active member
[ QUOTE ]
Nichrome wire from an electric fire element. Extract the whole wire length from a 1kw element.
[/ QUOTE ]
I used 'resistance wire' available from Maplins etc. The 'bow' I made from a split length of cane.
I reduced two 6' by 2' by 2" sheets of foam to 1.5" thick for cockpit cushions by this method. Laid the foam on a wood tray with raised edges of the correct height.
Hoping to do the same for the saloon cushions. They need a denser layer of foam at the base.
Nichrome wire from an electric fire element. Extract the whole wire length from a 1kw element.
[/ QUOTE ]
I used 'resistance wire' available from Maplins etc. The 'bow' I made from a split length of cane.
I reduced two 6' by 2' by 2" sheets of foam to 1.5" thick for cockpit cushions by this method. Laid the foam on a wood tray with raised edges of the correct height.
Hoping to do the same for the saloon cushions. They need a denser layer of foam at the base.
Rabbie
New member
Exactly! Why do some people on here rubbish items and tips like this. It is so efficient, my local foam shop guy uses a knife all the time.
Refueler
Well-known member
[ QUOTE ]
WARNING
Depending on the foam the fumes can be VERY TOXIC.
[/ QUOTE ]
Yes .. agreed ... go back and read latter part of my hot-wire post about well ventilated or outside.
Second most foams now used are not the old dangerous types anymore - unless of course boat has old foam jobs on it ... flame retardent, less toxic fume types ... etc.
WARNING
Depending on the foam the fumes can be VERY TOXIC.
[/ QUOTE ]
Yes .. agreed ... go back and read latter part of my hot-wire post about well ventilated or outside.
Second most foams now used are not the old dangerous types anymore - unless of course boat has old foam jobs on it ... flame retardent, less toxic fume types ... etc.
Refueler
Well-known member
[ QUOTE ]
Exactly! Why do some people on here rubbish items and tips like this. It is so efficient, my local foam shop guy uses a knife all the time.
[/ QUOTE ]
Don't think that anyone rubbishes use of an electric knife - just that there are other ways to do the job as well.
Exactly! Why do some people on here rubbish items and tips like this. It is so efficient, my local foam shop guy uses a knife all the time.
[/ QUOTE ]
Don't think that anyone rubbishes use of an electric knife - just that there are other ways to do the job as well.
