Dollar store circle cutter

Mister Occlusion · Dollar store circle cutter

Went to a dollar store today and looky what I found

With a $1 cheap-junk plastic circle cutter I can now make my own Jensen porthole gaskets. My largest hole punch, also seen in shot, is good enough to knock out the inside of the gasket.

The only downside?

If I attempt to carve out a circle in one go, the knife blade will spiral inwards, ruining the gasket.

What I find I have to do is punch the blade through the teflon, pull it out, swing the cutter a degree or two around, punch down again, rinse, wash, and repeat all the way around the circle. If that does not cut it out perfectly it at least perforates it well enough that I can tear out the teflon circle easily and cleanly.

Then it's just a matter of lining up and knocking out the centre hole. My punch is a shade undersized, but I can live with that. Once the gasket is emplaced it's a simple matter to carve the excess off with a sharp knife using the ring in the boiler itself as a guide.

Moral? It pays to walk through these shops that are so full of cheap rubbish and tat, even the aisles that men might otherwise avoid. - This thing was in the middle of the Frilly Crafts section

$1, and it comes with 2 spare blades.

And the best thing of all? .025 Teflon seals like a dream. No more leaky bloody portholes for me!

Wallace

That is a very handy tool, and I'm going to check out our equivalent shops.

I also see the hole punch you have.

They are very handy too, mine looks the exact same. About $6 for a big set from a cheap store.

Reid

Lacking an arch punch for the hole, you might find it easier to use small,
curved blade nail scissors to cut the inner diameter?

Thanks for the great tip, Mark. I'm gonna get one of those circle cutters soon.

MooseMan

I love those hole punches....something very therapeutic about knocking out gaskets with a great big hammer.

johnreid

Wow I am going to have to search through the entire store and look for that. Was it where the limited inventory of tools are, or with school/office supplies?

Reid

Bogstandard

For your little compass cutter, try holding the compass upright and stationary, and turn the material, I find this works for me when cutting PTFE sheet.
I also cut the OD first, then the ID. I find that hole punches tend to distort the material a little too much for my work.
If I want to make a few, I stick a piece of sheet onto a bit of plywood with double sided tape, then cut all the OD's first then all the ID's, it just peels off the tape afterwards, and doing it this way is easier to handle for cutting the ID's than the above method I suggested.
I bought mine years ago when they were first made by Olfa, I buy the cheapo ones just to get the spare blades, and sharpen them up with an Arkansas stone or diamond dresser.

You can make you own little punches up out of brass tube, they won't stand a lot of bashing but they do get the job done in soft gasket material. Just get a bit of tube the same diam as you want the hole and get a larger sized drill, and just put it onto the end of the tube and turn the drill as if you are trying to bore out the tube, you should end up with a nice countersink on the end of the tube, and a nice sharp edge, to resharpen just repeat the drill bit thing. If you want to do it with steel tube, just substitute a power screwdriver instead of your hand when turning the drill. They do tend to keep their edge a bit longer.

John

johnreid

I was doing some Internet searching and find that those are popular with the scrapbooking hobby and I would bet that they could also be found at the Wally World Crafts dept.

Steve_S

I'm also a big fan of cheap tat shops. You never know what you'll find!

Mister Occlusion

johnreid

My punched gaskets have that curve to them but I just let that part go with the shape of the boiler. Once heated a few times they seem to flatten out.
The main circle cutter use I see is the round sightglass washers. I have a spare set for Jensens, but if Smokey needs one the circle cutter might be of good use.
No big rush to find one, but will keep my eyes open as I shop in Dollar Stores etc.

Mister Occlusion

I found a length of copper pipe that was the exact right size for the ID of a Jensen porthole.

Reamed it out on the inside about 2/3 of the way, then turned a bit of a bevel on the outside with the belt sander to give it a nice sharp edge and cut about 2" of it off.

I punched out 6 gasket centres with it on a softwood board - probably pine or cedar (whatever my old 3" Model 70 came mounted on). I gave the inside a quick whisk with a file once to knock off a minor burr, otherwise I'm sure it will hold up proper for the limited number of gaskets I need to make.

I made the inner ones out of the .025 material and the outer ones out of the thinner stuff.... .010 or .015 I think it is... I forget, but it's at least half as thick. I figure the inner one is the more critical and the outer one is more of a buffer between ring and glass to equalize the pressure on the glass from the ring.. Anyway I redid my model 20 and it works dandy. Plus, since you do not rub any oil into these gaskets, you have absolutely zero film getting onto the sight glass (A problem that I had with the card gaskets).

The above mentioned tip about holding the tool still and moving the sheet worked wonderfully too. I planted the center spike well into my soft wood and also dug the very tip of the knife into the wood so that it could not flex. Just carefully turn the sheet into the knife and it cuts perfectly without spiraling inwards.

I couldn't be happier

Cranko

I mark ther outside diameter with a pen and cut it out with the sissors then take the inside diameter out with a hole punch. I use ice cream containerfor the medium , the lid for thin gaskets the lower portion for thicker