Rope cutter/Hot knife question

J

jane444blue

Well-Known Member
Joined
28 Jun 2010
Messages
127
Visit site
Does anyone have experience of using cordless versions of a hot knife? Trying to decide between cheaper butane ones, c£30 vs v expensive Marlow version type at c £200
Is it just a case of you get what you pay for, or intended use?
 
I have a corded Gonyiata (I think?) that I got for $25, and it is SO handy. Maybe not as good for all day, every day use, but I love it.
  • Rope, of course.
  • Shockcord. Actually hard to seal any other way.
  • Fabrics. Everything from sailcloth and Sunbrella to ripstop nylon for telltales. Just adjust the temperature.
  • Carpet. VERY handy. Cuts like butter, good edges.
  • Other weird melting jobs. Can be used to weld pastics. A few days ago I used it to bond fabric to polyethylene sheet.
Battery or corded, they heat fast, so unless you are cutting a whole sail, the on-time will only be a few minutes. They only take 2-4 seconds to warm up. I wouldn't do butane, I think. Electric is so much more versatile.
 
Have had one the £30 gas ones for years, works well, but to cut for dyneema needs to be left to really heat up, only other snag is the cutting part does eventually get dirty with melted rope, but obviously be cleaned up again if needed.
 
I have a couple of Iroda gas soldering irons on board.. They have had a huge amount of use over the years and I wouldn't be without them.

As well as the soldering tips, they each came with blow torch, hot air and hot knife tips..

I know it only takes a few seconds to change the tips but I have two to save even having to spend time swapping them!
 
Martin_J said:
Oh and I do keep a cutting block with each of them. It helps to have something to cut on if you want to cut rope neatly.
Click to expand...
We keep an old wooden cutting board specifically for this job. We often cut acrylic canvas with the hot knife as it seals the edges as it cuts.
We have a seperate gas soldering iron onboard for soldering. In my opinion, the proffessional spec hot knife is the way to go for canvas work, rope ends, webbings , etc. Maybe a bit over the top for the weekend sailor but very much on top of the job and will last many years. You see them in sailmakers lofts
 
I've got the HSGM hot knife cutter. Mains powered but used on the boat with a small transformer - 12v to 230v. Works well, bought used cheaply on ebay many years ago. German made, but quite expensive, cheaper ones available. In theory should only be used for 15 seconds at a time but I've used it for several minutes within problems.
 
Martin_J said:
Nice, but the marina might not be happy with me cutting with a hot knife just here..

View attachment 184899

The gas knife is still good for sealing the edge afterwards.
Click to expand...
a. In my shop I have one low bench with a 2'x3' piece of tin screwed down. Soldering and hot knife work. No fire worries if I leave a hot tool.

b. I have an 18" x 4' piece of tin I take to boat if there is something big. Mostly this is for cutting carpet. Any small block of scrap wood is fine for rope. Of course, a piece of lauan would do.
 
Martin_J said:
Nice, but the marina might not be happy with me cutting with a hot knife just here..
Click to expand...
I use a piece of tempered glass about 15cm x 60/70cm as cutting surface, they are sold around 10e as bathroom shelves, together with a metal straightedge. They can be used on pontoons, also on the kitchen/living room table without fear of damaging anything, including marital relationships :)
I use a Dremel butane pen for canvas (Versatip, just found the name), reasonably quick and a refill lasts several meters of acrylic fabric cutting.
 
I had a small butane hot knife, and found it very useful.
A couple of things to be aware of:
In the cockpit on a windy day mine took ages to get to heat, and sometimes didn't - not an issue as I was only using it for rope so could move the part in to the cabin for cutting.
After a while it became clear that the cutting blade was actually in two parts - the part that screwed on to the heater and the blade that wedged into that. The blade eventually came loose in the housing and stopped working so well, but that was after quite a lot of use.
 
Just bought a proper hot knife (hsgm) having had poor results from cheaper alliexpress models. More expensive though 150e versus 40e.
Have also ordered a cutting attachment which does away with the need to have anything underneath the fabric. Sailrite have a video of it in action. Very useful bit of kit.
Quite expensive from Sailrite and others but can be had for 2/3e from of course Alliexpress
 
I mostly use a mains-powered hot knife but I do also have a butane one. It works and is fine for cutting and sealing the odd rope. It's possible to make a crude hot knife by filing the tip of a 40 watt soldering iron.
 
Shamu341 said:
Just bought a proper hot knife (hsgm) having had poor results from cheaper alliexpress models. More expensive though 150e versus 40e.
Have also ordered a cutting attachment which does away with the need to have anything underneath the fabric. Sailrite have a video of it in action. Very useful bit of kit.
Quite expensive from Sailrite and others but can be had for 2/3e from of course Alliexpress
Click to expand...
Good point about the cutting attachment. I've used them, but did not get it for my knife (they are universal fit on many knives). I don't really do enough large projects for it to matter, and I don't think it works for carpet. (This is actually one of the main uses--my boat, friend's boats, carpet for runners and decks, and pet projects.)
 
Shamu341 said:
Just bought a proper hot knife (hsgm) having had poor results from cheaper alliexpress models. More expensive though 150e versus 40e.
Have also ordered a cutting attachment which does away with the need to have anything underneath the fabric. Sailrite have a video of it in action. Very useful bit of kit.
Quite expensive from Sailrite and others but can be had for 2/3e from of course Alliexpress
Click to expand...
We have the cutting attachment but couldn't get on with it. It seem to need more heat than the knife could generate to cut. It could be that the weight of the fabric we were using was too much for it
 
You must log in or register to reply here.

Share this page

Top