Backyard Aquaponics
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I am using 1 1/4" uniseals with a 2" hole.. Now I can't for the life of me get the pipe in. I've tried lubing it up but to no avail. I tried hammering it in I got so frustrated with it but that doesn't even work.

what gives?

Make sure you are pushing through from the wide side of the uniseal.

uniseals are meant to be tight, but if it's not under pressure they work fine in a SLIGHTLY oversize hole. if the hole is too big, the uniseal will pull out even after the pipe is put in.

Try something: remove uniseal, inset pipe into uniseal. Is this possible/easy? if not, you probably have the wrong pipe/uniseal combination.
pressure pipe has a different outside diameter to DWV pipe.

I can get it on but it is not super easy.. but easier than when it's plugged into the bed. Maybe I should file down the edges a bit?

Sure you cut the hole the right size? they are very specific on hole sizing. BTW you can only push them one way ie you can't pull it back out once in.

My holes may be a touch oversize, I can pull them out again, but it's one hell of an effort!

Uniseals can be very difficult to push pipe through. I found that the larger pipe sizes or the thicker the tank wall, the harder it is to push the pipe in. If the pipe is old or rough it is also harder to push in.
Rubbing alcohol is a good lube for getting things going (since it will evaporate and not leave any soap to kill fish.)
Pushing the pipe in if you don't have a good angle to exert pressure can be nearly impossible.
I think some people have gone to the extent of sanding down the insertion end of the pipe to help get it started or perhaps cutting the end of the pipe at an angle. I'm not sure how well either of those things work. I know I have pulled muscles when trying to push uniseals in from difficult angles.

agreed, I have skun my knuckles attempting to remove one of my tighter standpipes from a uniseal... the filter standpipe can be quite sharp, and there's not much room down there...

Yep I have exactly 2" hole.. maybe a hair over. I can't even get the pipe to where its like partially in to where the tough pushing it through starts to happen. I just can't even get it started. I don't think it's a lube issue. Maybe 1 1/4" is a bad size for uniseal. I think I'm going to have to file down the insert side

are you sure your pipe is the right diameter for the uniseal?
Try using DWV pipe, it will fit easier.

I must say that of all the uniseals the 1 1/4" inch size are not correctly made. Its takes cutting down the edge of the pipe to collapse part of it, using vaseline, and a rubber hammer to get that stuff through and then it might damage a thin tank. All other uniseals work perfect! That size I will not buy again!

Any one who is having 1 1/4" Uniseal problems, please send them to me that is the size I use most, and have no issues with them at all.

-hole size is very important!
-tapering the pipe can help (I had to do this with a 2" sch. 40 yesterday.)
-thin wall pipe is always easier.
-lube the pipe, lube the Uniseal, lube extra!
-"walk" the pipe in, go around in circles as you push and twist some (if you can get one side started, and you are patient the rest will go in)
-if you are going through a thick wall, then the Uniseal may need to be cut, it will be tight, really tight. It was made to have the last little lip on the back side of the Uniseal remain sticking out. It will still work, but it will be really tight. In this case, don't worry if in the process the pipe cuts the Uniseal a bit.

They "won't" leak.

heres the offical uniseal install guide

1. Cut hole to the Hole saw size indicated for the UNISEAL® you are using
Example 3" UNISEAL® = 4" Hole (Hole saw)
2. Ensure the hole is clean cut with sharp edges. Irregularities could cause
poor seating and ultimate leakage.
3. Insert UNISEAL® into hole with the wide side facing the pipe to be inserted.
4. Make certain that the pipe end to be inserted is clean cut. File the edges so
that there are no sharp points to cut the UNISEAL®
5. Using fish safe lubricant, lubricate the outside of the pipe end to be inserted, then
push the pipe through the UNISEAL® from the large flange side.
The co-efficient of friction of the rubber holds the pipe tightly in place.

That's all there is to it. Some tips will make this even easier.

Bevel the edge of the pipe about 30 degrees. This is just to get rid of the sharp edge on the pipe and to allow it to slide through the Uniseal easier.
Coat the pipe and the inside surface of the Uniseal with something safe for fish, this will allow the pipe to slide through the Uniseal

Part # DN# Pipe ID Pipe OD Hole saw Size
U038 10 3/8" 0.675" 17mm 1.00" 12.7mm
U050 15 1/2" 0.840" 21mm 1.25" 31.7mm
U075 20 3/4" 1.050" 27mm 1.25" 31.7mm
U100 25 1" 1.315" 33mm 1.75" 44.4mm
U125 32 1-1/4" 1.660" 42mm 2.00" 50.8mm
U150 40 1-1/2" 1.900" 48mm 2.50" 63.5mm
U200 50 2" 2.375" 60mm 3.00" 76.2mm
U300 80 3" 3.500" 89mm 4.00" 101.6mm
U400 100 4" 4.500" 114mm 5.00" 127mm
U600 6" 6.625" 168mm 7.00" 178mm

I finally got it. I had to cut part of the pipe down as ddman suggested. Once the pipe was "in" it moved very easily.. I just could not break the seal with the pipe as it was.

Everything is working fine now.. I have 1 1/2" pipe to try next.. I'll see if it is any different. But The solution for me was to just saw down a side of the pipe so that it makes a small portion of the pipe a little smaller so I can get it through the seal then just seat it further down where the pipe is full size.

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