Hot Knife

[regalman190]

Finally broke down and bought an Engel hot knife. Wow, what a difference. Cuts way better than the soldering gun.

It does create a lot more smoke and fumes, so I have a question for all who have one.

What do you do about the smoke and fumes coming off the fabric? Do you where masks, do you have a fan blowing it away from you, or do you use a hepafilter type air cleaner?

[Mike8560]

fan here or hold my breath. the fumes arnet as bad as melting zipper though I used to cut my plastic zipper and then melt the end to make a stop and boy thoose fumes would burn your nose. got dangerous when the zip would catch fire on my table somtimes now i just fold a tab of matching bindng over the end never caught on with the metal stops. for me.

[bobbin]

I have been using a hot knife since about 1993.  I haven't had real issues with the smoke, as the there is generally a cross breeze in the shop or, in the case of the first shop I worked for, the ceilings were really high (20'). 

I think hot knives are great.  They cut quickly and efficiently and the seared edge resists fraying.  My boss still cuts acrylics with scissors and then passes the small, paddle like hot knife over the cut edges.  Every piece is handled twice, requiring a lot of extra time, but using the Engel seems daunting for some reason. 

[Jim101]

I use one of those little desk fans in the shop when cutting with the hot knife.  It works great!

Just a side note...  For years I used the hot knife drawing it toward myself as I was cutting.  I was recently watching one of those Marine Canvas Training Institute videos on You Tube and saw the woman was pushing the hot knife away from her as she cut and you know what it actually works better that way.

I find you can keep the material more taut that way and actually keep a straighter line.

I wonder what else I've been doing wrong all these years  :o

Happy cutting!

Jim

[Mike8560]

 there is a foot that goese with he knife and if you use it you have to push away.
I find hang  the knife too slow.  and If you just sew and top stitch a seam it is rough especialy if on the gelcoat, for me its faster to use sissors ( spelling?) and bind inside seams then top sew.

[JuneC]

Pulling the knife towards you sounds really dangerous.  I push - when I use it at all.  Bet I haven't used mine in more than a year.  Like Mike, I find the edges too sharp for gelcoat and MUCH slower cutting than a pair of razor-edge scissors.  I don't "scissor" cut (open/close scissors) except on small shapes.  Just hold the scissors slightly open and push against the fabric.  Sunbrella separates like a dream cutting this way.  Centerfold binding on cut edges while topstitching finishes the edges. 

June 

[Mike8560]

  Centerfold binding on cut edges while topstitching finishes the edges. 

June 

i think this looks really nice also.

[Gregg @ Keystone Sewing]

Finally broke down and bought an Engel hot knife. Wow, what a difference. Cuts way better than the soldering gun.

It does create a lot more smoke and fumes, so I have a question for all who have one.

What do you do about the smoke and fumes coming off the fabric? Do you where masks, do you have a fan blowing it away from you, or do you use a hepafilter type air cleaner?

People are using soldiering irons?  Is that even possible?  LOL.

The Engle HSG-0 is a common item for a lot of our customers.  You can cut and seal anthing from light webbing to Sunbrealla.   

[bobbin]

I am surprised that "rough edges" are damaging gelcoat.  I've been working in the field for close to 20 yrs. now and there has never been a complaint about any abrasive action on gelcoat. 

My own thoughts:  a hot knife might cut more slowly than sCissors (Mike ;) !) but compared to the cost of binding and time to apply it... no contest.  However, if your customers are seeing excessive scratching on gelcoat, then you have to do what you feel best to keep them happy. 

[regalman190]

Greg...you can use the Engel blade on a soldering gun. But it doesn't work as well.

As for damage to gelcoat....haven't encountered that yet either.

[bobbin]

I have an Engel hot knife and in the instruction booklet there are a whole array of different cutting blades.  Yet I haven't seen any of them in the catalogues from the main suppliers we use. 

Gregg, do you guys handle the other cutting blades? I've often thought I'd like to have a couple of them, but have never bothered to research their availability. 

[rustyeod]

I use the Engle alot, but just recently the spring in the trigger broke.  I went to their website and found the replacement spring cheap but they had a $25 minimum (i think) but when I emailed that I didn't need anything else they mailed me the spring free of charge.  Good people.  Next time I need a blade I will go to their site and buy it.

[jojo]

Am I the only one who actually likes the smell of burning sunbrella?
I find that if you keep the trigger pressed in for a few seconds to let it heat up before you start cutting, you can go a little faster and have less burnup.

[Pegasus2007]

What do you guys use beneath the fabric when cutting with the hotknife?  We did use a piece of glass which worked well and didn't draw away the heat as fast as the aluminum rule we now use.

[jojo]

a sheet of formica...indestructable and cheap!