Mounting paper tubes at 90 Deg.

[PhilofKayDu]

I am trying to build craft items with paper core tubes. How do I attach them to each other and at 90 Deg. The ID of these tubes range from 3" to 20 3/4". Any sugestions would be very much appreciated! Being a new owner of a BT3K; I had a lot of questions. E.G. jigs, manual, hints, adaptations. I have to say this web site is GREAT! And all of you out there that have shared your knowledge and inventive attachments to the BT3K; THANK YOU VERY MUCH! Phil N. If anyone was wondering KayDu is my hobby business name.

[cabinetman]

I am trying to build craft items with paper core tubes. How do I attach them to each other and at 90 Deg. The ID of these tubes range from 3" to 20 3/4". Any sugestions would be very much appreciated! Being a new owner of a BT3K; I had a lot of questions. E.G. jigs, manual, hints, adaptations. I have to say this web site is GREAT! And all of you out there that have shared your knowledge and inventive attachments to the BT3K; THANK YOU VERY MUCH! Phil N. If anyone was wondering KayDu is my hobby business name.

WELCOME TO THE FORUM

Just a few questions.

What type of paper...like Sonotubes?

What are the wall thicknesses?

Are they to be glued at the ends creating a 90 degree corner, or, will they be glued with one part glued to another creating a "T". If there is a "T", will there be same OD sizes glued or different sizes?

If glued together, other than 90 degrees, will there be same sizes or different sizes?

Are the tubes all round, or are there square tubes?

How structural does the glue joint have to be?
.

[Mr__Bill]

To get the ball rolling here I'll make a few assumptions.

To join a smaller tube to a larger to make a T shape. Drill the larger tube and insert the smaller and then glue the heck out of it. Paper tubes need to have the glue area spread out much more than wood the glue joint should look like it was welded, with a bead of glue in the joint. Hot melt works great at this for smaller tubes, the size of paper towel tubes. Big ones like Sonotubes or the tube that is in the center of a roll of carpet or vinyl, you can reinforce the joint with staples or screws, screws need to have a pilot hold drilled first. Another way is to drill the tube and then cut it in the middle of the hole, this gives you the correct shape to fit snugly over the other tube, assuming it's of the same size. And yet another, if you have a drill press, get some sanding drums in the size of the tubing you will be using, again assuming small tubes, and sand the shape into the end of the tube, this way you can join a smaller tube to a larger and sand the larger profile in to the end of the smaller. Sonotubes can be cut with a jig saw with a fine blade to minimize tearing, then sand or file to the final shape. Use some thick epoxy glue for the joint, hot melt just isn't strong enough in it's sticking power to the paper tube. Sonotubes are also waxed and you need to clean the way off of it so the glue can stick.

At this point you're asking yourself how the heck to I drill a paper tube and not destroy the tube or my fingers. Use a hole saw and for the lightweight tubes do it by hand. Drill a clean pilot hole and then work the hole saw without the drill, by hand to cut the hole.

If you need for the finished project to have some strength you can fill the tubes with foam, the kind that comes in the spray can. If the joints are made such that foam meets foam the result can be rather strong.

OK now, lets hear how others would do this.

Bill, over here in the rain

[PhilofKayDu]

To cabinetman. I'm not sure what Sonotubes are. I am recycling from local businesses. These tubes are made from [brown paper sack] material wrapped and wrapped [round] to form many wall thicknesses. I am useing mostly 1/2". First- I start with 3/4" plywood as a base. Second- I attach an unspecified DIA. of tube at 90 deg. to plywood. Thired- I want to attach the same DIA. or different DIA. to Step 2. Creating a "T" at 90 deg.; or if I can do other angles that would be neat too. To Bill, I thought of deck scews and lag screws. But I did not think of epoxy. THANKS! What do you think about Liquid Nails?

[LCHIEN]

sounds like the ID is controlled but the OD is not?
1/2" wall thickness is pretty good.

you don't say what the objective is for beauty, "fluid or gas" connection and integrity, or mechanical strength.
For smaller tubes to larger tubes, for mech strength, drill thru both sides of the larger tube and then insert the smaller tube through and out the other side, the glue. This will work even better for angles other than 90 if you have a drill press with an angled table for precision angles.
You said tubes 3" to 20+", that of course will be an issue for drill bits, maybe hole saws will work. Getting a tight fit to unspecified/uncontrolled ODs may also be an issue. In this case drill the large tube for dowels which are precision (sort of) OD and insert the dowel in the larger tube, then attach the smaller tube with an ID that macthces the dowel to the dowel.

[cabinetman]

To cabinetman. I'm not sure what Sonotubes are. I am recycling from local businesses. These tubes are made from [brown paper sack] material wrapped and wrapped [round] to form many wall thicknesses. I am useing mostly 1/2". First- I start with 3/4" plywood as a base. Second- I attach an unspecified DIA. of tube at 90 deg. to plywood. Thired- I want to attach the same DIA. or different DIA. to Step 2. Creating a "T" at 90 deg.; or if I can do other angles that would be neat too. To Bill, I thought of deck scews and lag screws. But I did not think of epoxy. THANKS! What do you think about Liquid Nails?

It's still not clear about the application. For example, if there is a need for a through airway from attached tubes, and how structural the joint has to be. Generally speaking attaching the same size of OD tubing, there has to be an edge match. For different sizes, the smaller tubing should match the larger one. Hot glue and Liquid Nail would achieve a bond but their strength would depend on how structural the joint needs to be. IMO, a two part epoxy would be best overall.
.

[Mr__Bill]

If these are the paper tubes that you can unroll the paper from then gluing to the tube is just gluing to the top sheet of paper. Makes it harder to glue together and really hard to screw into the edge of the tubing.

Liquid nails should work fine, if the tube is as above you may have to saturate the edge to create surface to glue to.

Sonotubes are used to pour concrete pillars, they are paper cardboard tubes that have been waxed and come in various sized and lengths. Used on construction sites, when you see a concrete pillar that has a spiral pattern on the out side that pillar was poured in a sonotube.