Modifying a cylinder?

Hi to all pumpers, maybe you have some experience with this.

I am pumping with a thickwall cylinder, all was going well but a few days ago I got some soreness where the cylinder digs in so much. This is preventing me from pumping.

I have a 1.75 LApdist cylinder that is too small for me now and it has a foot welded on for comfort.

I want to get this foot off and transfer it to my thickwall cylinder.

Any ideas on how I can get this foot off without damaging it? I will probably only get one attempt :)
Is there anything I can use to breakdown the weld?

The only way I can think of is to use a fine toothed Coping or Fret saw but this might leave an uneven surface.

The plastic is “welded”? Years ago I saw an optician take a pair of broken plastic frame glasses, clean them, dab acetone on the surfaces and hold them together - the acetone, he said, melted the plastic temporarily, turning it into a gluey surface.

Maybe that’s how it’s welded together? But putting acetone on the weld would probably not do you any good. If you saw it off, you can probably use fine grit sandpaper, then finer and so on and finally the paper painters use for laquered surfaces to get a surface smooth enough to apply acetone to it.

Better practice on the top end of the old cylinder first.

There is a thread here somewhere about making your own pump that mentions using surgical rubber hose to make a cushion for the bottom of a cylinder. I used household silicone caulk, applying several layers one at a time just when the previous layer was starting to skin over. I don’t know how thick the walls are on that tube, but you may look into automotive vacuum or coolant hoses, split one down the middle, and attach and seal the end with silicone

Instead of doing what you’re proposing, you might want to consider the following alternatives:

- Plastidip. Some members have used Plastidip on thinwall cylinders without bases (such as aquarium gravel cleaner tubes), so it should work on your thickwall.

- Go to Amazon.com and do a search on Universal Silicone Replacement Donut Sleeve For Pumps. You’ll find seals to fit the base of your cylinder starting at $10. You may also find them at your friendly local sex toy shop or online vendor; they aren’t uncommon.

What kind of vacuum are you pulling? I’ve never had a discomfort problem with my thickwall.

mgus, welded is the term they used to describe how the foot (also their term) is stuck onto the cylinder.

I assumed it was welded by some type of super glue but don’t know for sure.
It is a really good joint with no glue or anything visible.

manage, yes I could use a silicone sealant instead of the foot.
I used silicone sealant on the inside of my cable clamp.

The thickwall cylinder is 3/16”.
I just wonder how good a seal I will get with that or with using a hose.

Lampwick, I am not sure what Plastidip is.
I will look on Amazon for the universal silicone replacement sleeves.
I pump at 4 HG and actually felt the discomfort at 3.5HG.

I can tell you that if it is an acrylic cylinder and was put together correctly they probably used a product called weld-on. This product actually softens both surfaces and “welds” them together as one. I think your best bet would be to find an alternative. Maybe find a local acrylic distributor and have them cut you the ring for the base.

BlueNun:

Sorry about that. I see that you are in the UK, and in checking out the Plastidip web site , it may be a North American product.

Plastidip is a plastic coating generally used for tools. You can dip it more than once for more thickness. Members here have dipped tube ends in Plastidip to build up a softer, more flexible edge. Perhaps there is an equivalent product in the UK.

Those are good safe levels for pumping; if you’re feeling discomfort at those levels, some kind of cushion would be a good idea.

Plastidip - or something like it - is available in Sweden, so it should be availble in the UK too.

Register - my bet is that this would be acetone, albeit in an expensive bottle.

Thanks for the replies, gives me lots of options.

Manage, what thickness are the walls of your thickwall cylinder?
Just wondering if 3/16” is standard.

If my math is correct both my LAP cylinders are 1/8” but they are not thickwall.

Yes my LAPdist cylinder is just under 1/8” thick, my thickwall is 3/16” so not much thicker.

I just wondered if 3/16” was standard for thickwall.

You can run some plastic insulating tape folded around the base of the cylinder. I did that with my first home-made pump when I used a plastic cylinder from those household sealant/filler pumps. It works OK but of course you can’t see what’s going on. But it makes a good starting point .

There is the problem of removing the goo inside but a water soluble filling is easier to move out. But do make sure it is clean as there could be a problem if some chemical attaches itself to you.

Some plastic or preferably rubber tubing to fit over the nozzle is best. Or you can cut the nozzle off and push the rubber tubing into the hole. But it has to be a tight fit. The vacumm can be maintained by using a clothes peg over the bent double hose to hold the vacuum

It’s not my original idea as a member did suggest it a couple of years ago.

Some people have had success “flaring out” the end of the plastic tube by using heat. Depending on the type of plastic it should be possible to make the tube end malleable with a heat gun for example. Heating the tube up needs to be done slowly enough to prevent burning or over melting. With the plastic in a pliable state, it could be formed over the neck of a glass bottle for instance, to give a flared end that should prevent the digging in problem you’re having. Of course there is some small risk the plastic is unsuited to this process or that you could otherwise mess it up.. Not something you’d want to do with with an expensive tube. You’d need to have a good think about all this first.

bluenun, I use chamois skin (pronounced “shammy”), which you can get at any auto supply store. Wash it thoroughly and then cut strips wide enough (at least 6-cm, or about 2.5 inches) and long enough so you can drape the mouth of the cylinder with two or three layers. About an inch should extend inside the cylinder and enough on the outside to allow you to secure it with a rubber band. The chamois skin becomes very soft and slippery when wet, but you should also use some kind of lube on your dick (to prevent it from sticking on the inside) and all around the base of the shaft (to assure a good vacuum seal).

Interesting and ingenious! You mean the synthetic kind, not leather chamois, right?