Mix and Pour Foam

[gm280]

Okay guys I have a general question about mix and pour 2lbs foam for boats. Can this type of foam be cut with a hot wire? I know some foams are able to be cut to different shapes using a hot wire. I use to fly R/C planes and we made wings out of foam and cut them to shape with a length of Nichrome wire and an adjustable power supply. Once you got to the correct temperature the foam would cut like butter and very cleanly also. So I'm wondering if the mix and pour foam can be cut that way... Has anybody tried it with either hot wire or hot knife...? :decision:

 

[mwe-maxxowner]

Re: Mix and Pour Foam

I've been told it can be cut easily with a regular carpenter's hand saw. I haven't read of anyone using a heated knife, maybe you could be the first to teach us!

 

[jigngrub]

Re: Mix and Pour Foam

I haven't heard of anyone doing it that way, but it cuts well with a carpenters handsaw.

 

[Streetgang]

Re: Mix and Pour Foam

Not sure why you couldnt do it but here is a wonderful thread by Grandad.

He cuts foam (not the pour in type) with hot wire. He is a true craftsman.

good luck

http://forums.iboats.com/boat-resto...tarcraft-holiday-reno-hull-repair-517895.html

 

[low277]

Re: Mix and Pour Foam

My first thought was of Grandad also, he made a hot wire cutter out of some stuff he already had. His thread is a good read.

 

[GT1000000]

Re: Mix and Pour Foam

I took the liberty of contacting the Hot Wire Foam Factory, which specializes in making different kinds of hot foam cutting tools...

My question...

Using A-B Expanding Foam as a floatation aid in a boat...
The stuff you get that comes in liquid form, mix equal parts A & B...
Once it has expanded and cured, can it be cut with the Hot Wire Method?

Their answer...

Cutting polyurethane foam with heat gives off toxic fumes.
We have two tools that will probably cut this lower density PU foam, the Industrial Knife and the 2x4 Compound Bow:
Hot Wire Foam Factory
They will soot up and have to be cleaned after a few cuts. If the PU residue carbonizes on the blade it will stop cutting and need to be wiped off.
You can always send a sample to us for free testing

 

[colbyt]

Re: Mix and Pour Foam

Not to hijack but to tag along with a follow-up question is this dense enough for use on a boat?

 

[tpenfield]

Re: Mix and Pour Foam

2 lb foam is typical flotation foam for boats . . . 4 lb would be more structural.


I *tried* to cut the 2 lb foam with a hot wire, in a similar fashion to cutting out an R/C airplane wing as you described. It seemed to take way too much heat and produced a tremendous amount of toxic smoke. So, a bagged it and went with a more conventional cutitng method.

 

[Woodonglass]

Re: Mix and Pour Foam

I have to agree...Too dense to be cut via Hot Wire. Stick with a Saw. Works really well.

 

[gm280]

Re: Mix and Pour Foam

Okay guys I hear yea... I was think (that always gets me in trouble :facepalm: ) that I could pour foam into one section and hot wire cut it smooth before pouring foam in the adjacent area. That way I could pour all the foam and then install the flooring so I knew all the areas were filled properly... At lease that was my thought... I knew hot wire (Nichrome wire) would cut foam for R/C airplanes so smooth you would think it was pour from a mold... I guess I could cut it with a hand saw. But I know that will create some crumbs of foam to clean up before installing the flooring material... Not a show stopper though... :decision: Anyway, thanks for the replies...I'll heed the words!

 

[glenn property of pam]

Re: Mix and Pour Foam

Okay guys I hear yea... I was think (that always gets me in trouble :facepalm: ) that I could pour foam into one section and hot wire cut it smooth before pouring foam in the adjacent area. That way I could pour all the foam and then install the flooring so I knew all the areas were filled properly... At lease that was my thought... I knew hot wire (Nichrome wire) would cut foam for R/C airplanes so smooth you would think it was pour from a mold... I guess I could cut it with a hand saw. But I know that will create some crumbs of foam to clean up before installing the flooring material... Not a show stopper though... :decision: Anyway, thanks for the replies...I'll heed the words!

take a piece of old ply then cover with plastic. pour then hold ply over the pour and remove before it sets fully or it will stick to the plastic

p.s buy a hand blender and use one blade as the mixing realy does affect the expansion

 

[Jim Hawkins]

Re: Mix and Pour Foam

I tried to foam a hull in one pour but was way under in calculating the amount so I decided to do it in sections. I took several pieces of sheet aluminum and greased one side then I picked a section to pour and after pouring placed the aluminum over the pour held down by bricks resting on top of the stringers. When the foam was done expanding I pulled up the aluminum, regreased and moved ahead to the next section.

When I was done, I had completely filled all voids with little waste but all the different pours made slight mounds so I took the blade of an old straight blade carpenters saw and sliding it left and right across the tops of the stringers, leveled off the foam to a very flat surface. In my case I was using high density foam and glassing right on top of the foam.