O-Ring Bolstered Constrictors

The most basic problem with a really simple liner is its entrance tends to be deeply conical, or funnel shaped, on both ends. When the liner is tensioned it cannot help but create such a shape unless there is something to restrict it. Fortunately one can get a lot of help from the constrictor, which will help brace the entrance end of the receiver and partially avoid a funnel shaped entrance.

Even a pronounced funnel shape is not a problem on the cap end of the receiver. But on the entrance end of the receiver, this is a major invitation to air leakage and failure of the seal around the shaft of the penis while in use.

What one really wants is a front end that when finished would be a right angle. Similar to a flat latex plate with a tube fastened into the center of it. It would be flush across the front. This cannot be achieved simply because there is tension on the latex liner from end to end which is working to pull it down into some amount of funnel shape on each attachment end.

But this funnel shaping can easily be countered by supporting the "flange" part of the liner, the part where it comes up and over, at the entrance end of the receiver. You want something that is nice and round and firm.

One good way to do this involves O-rings. This are rather stiff rubber rings used for all kinds of sealing applications. You can get them at auto shops for instance. What you are looking for are those made of thick rubber rod formed into large rings. The sizes to look for are designated 326 and similar numbers. They should be close to 3/16 inch rod and formed into circles from 1.5 to 2 inches internal diameter.

A particularly useful size is 326, made of 3/16 inch rod and a bit less than 2 inches in outer diameter. Such an O-ring is just a bit less than the diameter of the 2 inch receiver housing and will almost, but not quite, slip inside. The size of O-ring one size smaller than this can also work, the one which will just slip inside. Sizes like 325, 326, 327 and 329. Unlike the natural latex of the liner material, the O-ring material is more durable and has a longer shelf life. So you can reuse O-rings many times.

You may even recognize these O-rings. They are sometimes sold at rather inflated prices as erection sustainers, though here we are interested in larger sizes than usually used for that purpose. They are not to constrict, but to shape the entrance. We have a latex sleeve in place to provide constriction and seal.

The first number designates the diameter of the rod, and the second one designates the diameter of the circle it is formed into. Actually the numbers are in 1/16ths of an inch.  The first number (3) means the rod part is 3/16th in diameter and the circle is 26/16ths or 1 5/8 inch diameter, in the case of a 326. In general I have found the 200 type O-rings which are only 1/8 inch rod material to be a bit wimpy for this application.

It is not easy to find the 400 series which would be 1/4 inch rod material. It also appears that this series starts with I.D.s of about four inches or so, and are not made in small sizes useful here. That leaves the 300 series as the best bet. For two-inch receivers the prime sizes would range from 325 on the small side, 326, 327 and 329 on the large side. The even larger sizes of 333 and 337 might be useful for the 2.5-inch receivers, but I have never tried O-rings with the 2.5-inch tubular housings and the 3/16 inch rod material seems a bit wimpy on such large diameters..

You use these O-rings by simply placing one on top of the installed constrictor. The constrictor will keep it from being forced into the tube itself. Now just install the liner on top of the O-ring, causing it to be trapped between the liner and the constrictor. If this o-ring usage is unclear we provide:

Detailed Description of Installing an O-ring

What the o-ring does is force the front of the receiver to be reshaped when the liner is tensioned and installed on the cap end. You can create a finished receiver rebuild that ends not in a funnel, but a rather sharply rounded entrance end. The liner material is braced by the O-ring which in turn is supported by the constrictor and the upper edge of the tubular housing. This provides a much better shape to the critical sealing area at the front of the constrictor.

Virtually all of my most effective receiver designs have used this O-ring trick to reshape the entrance area and avoid the pulled down funnel shaped entrance. You can now use significant end to end tension on the liner and still avoid a deep troublesome funnel on the entrance end. End-to-end tension is one of the parameters you can beneficially adjust in customizing liners, from barely tensioned and floppy to nice and tight from end to end. The O-ring trapped between the constrictor and the liner will buttress and support the entrance end and effectively resist the tension of the liner trying to pull it down into a long tapered funnel.

12/03