Ok, so I've been makin hoops for awhile and just started making polypro's a few months ago. I know the whole how to do it, one size down tubing used for the connector, rivet one side, put button in other side for collapsible yada yada I get that.
My main issue is the f***ing polypro tubing is NOT wanting to slide inside of the larger tubing for the connection. I've tried everything, heating it, pushing it, spraying it with pam (true story, didnt work) etc etc. Anyone have a tip hint or trick to getting the polypro connection to go in smoother? I can usually get it in about an inch or 2 then it refuses to move. and I use a 6 inch connection so that is not gonna cut it for me.
lol well my connectors are normally 4 in. So it's just 2 in. in both side of the hoop. I find the longer the connector you have issues like that, and because the longer the connector it could cause a straight spot in the hoop where it's connected. Basically your problem is that the connector is curved and the tubing not so much, since polypro is hard plastic it's harder to get it in. I'm surprised heating the tubing did not work. what diameter of polypro are you using. the 5/8th OD?
Sand it down a little.
"It" being the inner tube
Also, side note... heat causes things to exand, so you would have needed to heat the outer and cool the inner, but I don't think that would really help. But you can for sure sand the inner tube down a little more to get it to the right size to slide into the bigger outer tube.
I have had this same problem! Do you get your tubing from hoopsupplies.com... I found that you have to use the large coil polypro with the small coiled inserts (i order 5/8 by the foot and cut my own). For whatever reason the 5/8OD inserts dont fit into the 3/4OD unless the 5/8 is from the small coil and the 3/4 is from the large coil. I think the 3/4OD small coils compress the tubing to much and it just doesnt fit. Its very strange.
I figured this out because my first order of 50ft of 3/4OD had no problems with the connectors. Then I ordered 100ft of 3/4OD small coil and they wouldn't fit. It was seriously frustrating until I talked to the girl at hoopsupplies and she said another customer was having the same problem and that the 5/8 needed to be cut from the small coil and for whatever reason it fits. She even sent me new 5/8 cut from the small coil and it works fine now. That or you could just use HDPE connectors, they seem to fit fine no matter what.
Now when I order I make a note to cut the 5/8 from the small coil. Send them a message their customer service is excellent!
Ha! I think I'm the "other customer." I had the same problem, and Sunny went way above and beyond to get me the right (small coil) tubing in time to finish making hoops for a festival where I was vending.
That said, you have to be careful/aware about polypro. I ordered from U.S. Plastics because they were very affordable, but their polypro tubing is thicker, so I made a few hoops by spending hours sanding down connectors to fit. This mostly worked, but in the end they were weaker - only one broke after lots of use including fire, but it was clear that they were not up to par. Then I went with McMaster-Carr, expensive but very reliable in terms of product specs. Then I found Hoopsupplies.com... cheaper and nicer to give the business to fellow hoopers, but even then issues like the above can happen (good thing about hoopers is they'll totally understand the problem and work with you to fix it).
I also recently started playing with colored polypro which is a major headache as the colorants actually change the characteristics of the plastic itself so you get significant variances from one color to the next.
I make a lot of collapsible - multi-segments with pushbutton connectors - polypros so the perfect fit of the connectors is vital to the functionality of the hoop. I recently made a batch of these with mix-n-match color segments, so each color had to be worked on so they would each fit each other consistently. I'll just say that was the last time I'll make those!
If you're not making it collapsible, heat only the outer tubing (as Sarah said) and it should go in. Or if you're making it collapsible, you can heat the outer, slide the connector in and work it around as the outer tubing cools so it stretches out a bit and repeat until it's the right size. Also, you can use a shorter connector (I use 2").
ive had the same problem...i heated the tubing in hot water, although it left the connection "slightly" morphed it worked...hope you find a way!
omg polypro is such a bitch. if you can make an even cut down the center of the insert to take a cm or 2 out you can then bite on it to squish it together and then it should slide right in. but if its not even it looks shitty. bah. i hate that you can see the insert anyways.