Plastic clamps for hoophouse

BigVanVader · January 20, 2015

Has anyone used clamps like these? http://http://www.greenhousemegastor...pvc-fittings_1
If so how effective and where did you buy them?

I need some for a coldframe but apparently not all of these clamps are made from the same plastic and some dont work. Thanks!

luigiwu · January 20, 2015

I bought the 1/2-inch ones for my 1/2-inch Schedule 40. They are extremely tight-fitting,more so than I would like, and I'm using 4mil sheeting. I'm curious how the 3/4-inch would fit...
I just measured the inside diameter of the clamps is 3/4-inch. The outside diameter of my 1/2-in schedule 40 pipe is 7/8-inch. So the 1/8-inch differential is making the fit super tight.

Does someone here have the 3/4-inch clamps who can measure that?

Perhaps they stretch and become less tight over time?

I think I've read the you have to either paint or put tape over the pvc pipe to separate it from the PLASTIC you'll be using though.

Worth1 · January 20, 2015

Quote:

Originally Posted by luigiwu

I bought the 1/2-inch ones for my 1/2-inch Schedule 40. They are extremely tight-fitting,more so than I would like, and I'm using 4mil sheeting. I'm curious how the 3/4-inch would fit...
I just measured the inside diameter of the clamps is 3/4-inch. The outside diameter of my 1/2-in schedule 40 pipe is 7/8-inch. So the 1/8-inch differential is making the fit super tight.

Does someone here have the 3/4-inch clamps who can measure that?

Perhaps they stretch and become less tight over time?

I think I've read the you have to either paint or put tape over the pvc pipe to separate it from the PLASTIC you'll be using though.

I think your problem is the very small size you are dealing with.
The smaller size doesn't give you much linear material to bend and stretch.
Sort of like a very stiff small spring.
The outside diameter of 1/2 PVC pipe regardless of what SCH it is, is .840.
This calculates to 21/25 of an inch.
7/8" is .875 and 13/16 is .8125 the closest to a fraction for 840 in real fractions is 27/32 which is .8438.
3/4' inch PVC OD is 1.315 or around 1-1/16.
I cant find the actual dimensions for the snap clamps anywhere but it looks like the 3/4 clamps would be too loose on the 1/2 pipe.
One you would have a problem with the differing radius and second the clearance would be too loose.
You want the clamp to be a wee bit smaller than the OD of the pipe so it will hold tightly.
Just from a wild guess I would think that the inside diameter of the 3/4 clamp would be around 15/16"
That would be around 1/8 smaller than the OD of 3/4" PVC pipe.

Worth

Worth1 · January 20, 2015

Quote:

Originally Posted by BigVanVader

Has anyone used clamps like these? http://http://www.greenhousemegastor...pvc-fittings_1
If so how effective and where did you buy them?

I need some for a coldframe but apparently not all of these clamps are made from the same plastic and some dont work. Thanks!

I haven't used them but from what I have read the biggest complaint is the corners aren't rounded.
This causes the plastic or material to be cut.
An easy fix would be to put about a 1/8 to 1/4 radius on them with a disk sander.

Worth

Cole_Robbie · January 20, 2015

Your link doesn't work. I think you mean this link:
http://www.greenhousemegastore.com/p...pvc-fittings_1

I would put a couple of screws in it if you want to make sure it stays in place.

FarmerShawn · January 20, 2015

I use some 3/4" clamps over 3/4" plastic pipe to seal off the edges of the roll-up sides on my small (12X12) greenhouse for the winter, and they work great for that.
I use 1/2" clamps on 1/2" electrical conduit bent into quickhoops, and am less impressed. They seem tight, but a good wind that gets under the plastic will lift it right off every time, despite the clamps and the added weights along the edges. I still use the clamps, but only to hold things in place until I can loop rope back and forth over the hoops to hold the plastic in place long term. It's a pain, but I was able to keep my peppers going for a full month after first frost, then I moved the whole thing over the leeks and brussels sprouts, and kept them going right up until snow, another month. So I find them handy, but not sufficient by themselves.

FLRedHeart · January 20, 2015

I have a small hoop tunnel I had to close off with another cheap 3 mil plastic for a few nights. My tunnel is made with with 3/4" double paint coated PVC. Before the paint it is a tight fit, but after the paint it was not doable without deforming (or ripping) the plastic. For the "clips", I cut about 40% of the circumference out in a jig of 6-8" pieces of 1" sch 40 pvc and rounded them with one of those orange tree shaped dremel grinding stones. I thought that by getting the right curve it would work, but I just couldn't. Maybe these clamps are all made from the same 1" pvc stock I used and having both the paint and plastic even bending it, it might not fit, I had looked at them, but the project just got too expensive so that's hopw I ended up and need to do something better if there is another try.

BigVanVader · January 20, 2015

Thanks for al the replies, and yes Robbie sorry for broken link but that is what I had meant. I will be using these on 3/4 inch water pipe with 1/2 inch rebar inside the pipe, so there is quite a bit of empty space between the rebar and pipe. I will be using 6 mil plastic. My thought was that the space in between the two would hopefully provide better grip for the clamps since there will be some give? Idk either way I'm going to have to try them out to see if they are any good.

Worth I like your idea of rounding the edges, I'm not rich and cant afford to ruin my greenhouse plastic.

Worth1 · January 20, 2015

Your welcome VanVader.
I need to get off my lazy rear go out and buy a bottle of argon and weld up a green house.
I have a TIG welder hole saws a drill press, benders and intend on using 3/4 EMT.
I have no excuse for not doing it.

Worth

salix · January 20, 2015

For what it's worth, when I've run out of those clamps/clips (which are sometimes difficult to apply and remove) we sometimes just use a 3 inch piece of old rubber hose with a slit down one side. Easy to cut with scissors or pruners etc. and round the corners.

BigVanVader · January 20, 2015

Thanks salix, I have a few old hoses I could use to try that out as well.

Worth a real metal greenhouse is still just a dream for me. I looked at some kits but the cost was to high. I may try to make my own hoops with chain link top rails and a bender jig if I make any money from my plants this year. Otherwise PVC and other cheap diy ones will have to suffice.

Wi-sunflower · January 20, 2015

I used some clamps on my PVC high tunnel a couple of years ago and they don't really hold if there is any wind. I also did the "lace up" thing with Paracord. That works great.

I have made some DIY clamps with the black PVC water line stuff that worked as good if not better than those I purchased. Take a small piece of the pipe you want to clamp to to the store with you and stick it in the end of some of the black water lines til you find a size that is a decent but a bit loose fit. A bit loose to allow for the plastic. On the project I did, I has some metal conduit type pipe and a size larger of the black pvc worked.

Cut about a 4 inch piece / clamp you want. Then cut a slit across the piece. That's all you need to do but you could round edges if you want. They will go on a bit hard. You need to start on 1 end and kind of rock them in place. They come off even harder and you may need a flat screw driver to pry them a bit. If you want easier off and on, cut out a bit of the circumference of the piece but not too much.

Carol

BigVanVader · January 20, 2015

When you say black PVC do you mean flexible polyethylene or the stiffer PVC drain type pipes? I'm actually otw to Lowes ATM so I can grab some but want to be sure of what type you mean. PVC seems it would be to stiff to get on with such a small split in it. Thanks for the help.

Wi-sunflower · January 21, 2015

Yes, I guess I meant the black poly type. Not the corrugated drain type.

Sometimes I have problems finding the right words these days.

Carol

natural · January 21, 2015

I tried to use PVC clamps to attach to pvc pipes for my makeshift end-wall "doors". I tried several kinds of pvc clamps and had issues with all of them. I finally gave up and bought several of these clamps. These worked great for me (these do NOT detach). However, I only need a few since I only used these for 2 pieces of pvc pipe (my 2 end "doors".

January 20, 2015	#1
BigVanVader Tomatovillian™ Join Date: Mar 2014 Location: Greenville, South Carolina Posts: 3,099	Plastic clamps for hoophouse Has anyone used clamps like these? http://http://www.greenhousemegastor...pvc-fittings_1 If so how effective and where did you buy them? I need some for a coldframe but apparently not all of these clamps are made from the same plastic and some dont work. Thanks!

January 20, 2015	#2
luigiwu Tomatovillian™ Join Date: Jun 2013 Location: ny Posts: 1,219	I bought the 1/2-inch ones for my 1/2-inch Schedule 40. They are extremely tight-fitting,more so than I would like, and I'm using 4mil sheeting. I'm curious how the 3/4-inch would fit... I just measured the inside diameter of the clamps is 3/4-inch. The outside diameter of my 1/2-in schedule 40 pipe is 7/8-inch. So the 1/8-inch differential is making the fit super tight. Does someone here have the 3/4-inch clamps who can measure that? Perhaps they stretch and become less tight over time? I think I've read the you have to either paint or put tape over the pvc pipe to separate it from the PLASTIC you'll be using though. __________________ Subirrigated Container gardening (RGGS) in NY, Zone 7! Last edited by luigiwu; January 20, 2015 at 08:14 AM.

January 20, 2015	#6
FarmerShawn Tomatovillian™ Join Date: Dec 2011 Location: Vermont Posts: 1,001	I use some 3/4" clamps over 3/4" plastic pipe to seal off the edges of the roll-up sides on my small (12X12) greenhouse for the winter, and they work great for that. I use 1/2" clamps on 1/2" electrical conduit bent into quickhoops, and am less impressed. They seem tight, but a good wind that gets under the plastic will lift it right off every time, despite the clamps and the added weights along the edges. I still use the clamps, but only to hold things in place until I can loop rope back and forth over the hoops to hold the plastic in place long term. It's a pain, but I was able to keep my peppers going for a full month after first frost, then I moved the whole thing over the leeks and brussels sprouts, and kept them going right up until snow, another month. So I find them handy, but not sufficient by themselves. __________________ "Red meat is NOT bad for you. Now blue-green meat, THAT'S bad for you!" -- Tommy Smothers

January 20, 2015	#7
FLRedHeart Tomatovillian™ Join Date: Aug 2014 Location: FL 8b/9a Posts: 262	I have a small hoop tunnel I had to close off with another cheap 3 mil plastic for a few nights. My tunnel is made with with 3/4" double paint coated PVC. Before the paint it is a tight fit, but after the paint it was not doable without deforming (or ripping) the plastic. For the "clips", I cut about 40% of the circumference out in a jig of 6-8" pieces of 1" sch 40 pvc and rounded them with one of those orange tree shaped dremel grinding stones. I thought that by getting the right curve it would work, but I just couldn't. Maybe these clamps are all made from the same 1" pvc stock I used and having both the paint and plastic even bending it, it might not fit, I had looked at them, but the project just got too expensive so that's hopw I ended up and need to do something better if there is another try. Last edited by FLRedHeart; January 20, 2015 at 03:54 PM. Reason: added that I used 1" sch 40 PVC

January 20, 2015	#10
salix Tomatovillian™ Join Date: Dec 2007 Location: north central B.C. Posts: 2,310	For what it's worth, when I've run out of those clamps/clips (which are sometimes difficult to apply and remove) we sometimes just use a 3 inch piece of old rubber hose with a slit down one side. Easy to cut with scissors or pruners etc. and round the corners. __________________ "He who has a library and a garden wants for nothing." -Cicero

January 20, 2015	#5
Cole_Robbie Tomatovillian™ Join Date: Jun 2012 Location: Illinois, zone 6 Posts: 8,407	Your link doesn't work. I think you mean this link: http://www.greenhousemegastore.com/p...pvc-fittings_1 I would put a couple of screws in it if you want to make sure it stays in place.

January 20, 2015	#9
Worth1 Tomatovillian™ Join Date: Feb 2006 Location: Den of Drunken Fools Posts: 38,539	Your welcome VanVader. I need to get off my lazy rear go out and buy a bottle of argon and weld up a green house. I have a TIG welder hole saws a drill press, benders and intend on using 3/4 EMT. I have no excuse for not doing it. Worth

January 20, 2015	#12
Wi-sunflower Tomatovillian™ Join Date: Nov 2008 Location: Wisconsin Posts: 2,591	I used some clamps on my PVC high tunnel a couple of years ago and they don't really hold if there is any wind. I also did the "lace up" thing with Paracord. That works great. I have made some DIY clamps with the black PVC water line stuff that worked as good if not better than those I purchased. Take a small piece of the pipe you want to clamp to to the store with you and stick it in the end of some of the black water lines til you find a size that is a decent but a bit loose fit. A bit loose to allow for the plastic. On the project I did, I has some metal conduit type pipe and a size larger of the black pvc worked. Cut about a 4 inch piece / clamp you want. Then cut a slit across the piece. That's all you need to do but you could round edges if you want. They will go on a bit hard. You need to start on 1 end and kind of rock them in place. They come off even harder and you may need a flat screw driver to pry them a bit. If you want easier off and on, cut out a bit of the circumference of the piece but not too much. Carol

January 21, 2015	#14
Wi-sunflower Tomatovillian™ Join Date: Nov 2008 Location: Wisconsin Posts: 2,591	Yes, I guess I meant the black poly type. Not the corrugated drain type. Sometimes I have problems finding the right words these days. Carol

January 21, 2015	#15
natural Tomatovillian™ Join Date: Feb 2006 Location: North GA Posts: 530	I tried to use PVC clamps to attach to pvc pipes for my makeshift end-wall "doors". I tried several kinds of pvc clamps and had issues with all of them. I finally gave up and bought several of these clamps. These worked great for me (these do NOT detach). However, I only need a few since I only used these for 2 pieces of pvc pipe (my 2 end "doors".