Help for second sourcing solar pool heating panel leak plugs

[rock]

I need to repair what the manufacturer calls 'dimple leaks' in my solar heating panels for my pool - but I can't find the right plugs on the secondary market.

The manufacturer recommends using four plugs per leak .

The rubber plugs from the manufacturer cost about $55 per 100 count (which will only fix 25 leaks), so I was hoping to second source cheaper plugs.
After diligently searching, I found 'very similar' plugs for $5 per hundred count (see below).

These shorter plugs work - but because they are a tad too short, they are commensurately harder to install properly.

My basic question to experienced users is:
Q: Do you know where I can get rubber stoppers that are at least 7/8" long, while still being 1/4" on one end, and 1/8" on the other end?

Note:
The closest I can find at McMaster-Carr (PN 6448K88) is 3/4" long, 1/4" on one end and 1/8" on the other end.
Likewise with RubberDynamics.com (PN TPE0250-0750) & WidgetCo.com (PN 7-R000000-EPDM-RS).

 

[cramar]

Re: Help for second sourcing solar pool heating panel leak p

Some people advocate using screws, not sure if that works but I know some say it does.
If you search the forums there may be some threads on it.

 

[rock]

Re: Help for second sourcing solar pool heating panel leak p

Some people advocate using screws, not sure if that works but I know some say it does.
If you search the forums there may be some threads on it.

Thanks. I've read 'everything' on this topic, including the use of stainless steel screws.
I need 100 of them a year, so I would think that stainless steel screws, even if they do work, have to be 'vastly more expensive than rubber stoppers.

In addition, I've heard it all about the 'glues' to use. I've tried a half dozen, and even the manufacturer says they're all doomed because they say not much sticks to polypropylene.
Some people say they work - but I have yet to find an expoxy, cement, or glue that will hold against the 30psi that the manufacturer says is the pressure of the pump pumping against it.

I thought the reason the plugs hold is that they deform and expand; but the manufacturer technical support says it's a friction fit.
He recommended four plugs per hole (but that would be about 200 plugs per year).

My source of cheaper plugs works OK - but - it would be better if I could find them a tad longer.
This is the size I'm looking for (the critical dimension is the 1/4"):
1/4" wide at one end, and 1/8" wide at the other end (less critical), and 7/8" inch long or so (nice to have as it makes it slide in easier)