Guttering T-Joint

[DonGray]

Hi

Firstly apologies for this not being directly a plumbing question, but I'm in a bit of a bind and I was hoping to find some help. It's more of a hobby/home project.

I have numerous lengths of 65mm square Floplast uPVC downpipe, and I am wanting to do a series of butt joints to create essentially a series of T-Joints and make a framework.

See attached sketch.



The height of the upright you see on the right is about 900mm, and the width is about 500mm, so there is quite a span between joints. The frame will be outside 24/7 and regularly handled and moved so the joints need to be strong. It will be lifted by hand by the top of the right hand vertical.

I have tried using solvent weld on the edge of one tube and butt it against the flat on the adjoining piece. Although this was stronger than I thought it might be, it wasn't strong enough.

I've also tried reinforcing the joints with a series of 90° PVC angles and flat bar bridge plates across the joints. Although this helped, it doesn't look very neat.

I'm running a trial now using the solvent weld technique, and silicone sealant in the joint.

I've done some trials using essentially an extension which protrudes from the end of one tube and inserts into a cut out into the adjoining tube, which I have glued and riveted. This is the best joint I've had so far, although the cut out in the adjoining pipe is difficult to get neat with the tools I have.

Has anyone got any other ideas?

Also, eventually I will have to paint the frame, which needs to be durable. I have done some trials by scuffing the surface, rubbing with acetone and spraying. Although the finish looks ok, the durability is poor. I have some plastic adhesion promoter on the way so will give this a try, but would be interested in anyone's experience?

Once again, many thanks for reading, and I look forward to your comments.

Gray

 

[Ben-gee]

I have a couple of ideas, what is the purpose of this item?

 

[Basher]

If you're prepared to spend a bit over £1 on a Floplast joint, here's a possible option -

Using fitting illustrated below, where pipe appears to fit into top, and fit outside bottom:
Cut out opposite sides of top section, invert and glue over the bottom horizontal section where you need the joint. Insert vertical and glue it in. Done.

 

[DonGray]

If you're prepared to spend a bit over £1 on a Floplast joint, here's a possible option -

Using fitting illustrated below, where pipe appears to fit into top, and fit outside bottom:
Cut out opposite sides of top section, invert and glue over the bottom horizontal section where you need the joint. Insert vertical and glue it in. Done.

Thanks for the reply. Funnily enough, I spotted these on the Screwfix site this morning. I am picking up a set tomorrow to do exactly what you suggested!!!!

Ben-Gee - THe frame is a "wing" used for dog agility. They come in a set of two, spanned by a pole. A point to note - the will be an angled bar connecting the two upright, I just haven't drawn it in yet.

Whilst I am on the information hunt - another problem I am going to come up against - at some point I will need to cut some 16mm square "holes" on one of the verticals to support the pole. I have looked at a mortice cutting bit, intended for a pillar drill, I just need to find someone with a pillar drill I can use. Alternatively, I can use a dremel.

Thanks again for your answers. Much appreciated!!

 

[Ben-gee]

Ok, so sort of a high jump.

If it were me, for construction and stability, I would insert a bit of timber (cls) into the bottom horizontal and drill/screw through the downpipe into the timber.
Use stainless steel screws and penny washers, you’ll have ‘plastic coated wood’ which should be weather proof ( blob of silicone at each screwhole if you wish)

 

[DonGray]

Ok, so sort of a high jump.

If it were me, for construction and stability, I would insert a bit of timber (cls) into the bottom horizontal and drill/screw through the downpipe into the timber.
Use stainless steel screws and penny washers, you’ll have ‘plastic coated wood’ which should be weather proof ( blob of silicone at each screwhole if you wish)

Hi. Many thanks for the reply. A high jump is exactly what it is. On my initial prototype, that's how my joint was. I did find it tricky to get a tight fit of the wood in the tube, had to chamfer the edges for the tube edge bend radius etc, which I needed for the screw to pull up against. I've since moved onto a rivited joint, which is similar in principle.

 

[Deleted member 120897]

For the holes, perhaps some pilot drilled holes and mini hacksaw? DeWalt 20tpi Metal/Plastic Mini Hacksaw 12 - https://www.NoLinkingToThis/p/dewalt-20tpi-metal-plastic-mini-hacksaw-12-300mm-/465HJ?tc=JT7&ds_kid=92700055262507126&ds_rl=1244066&gclid=CjwKCAjw95yJBhAgEiwAmRrutBGhxX70t3aONe-f8794NorXP_6WqGH9RlDuE-pRy33mnaLZVtdqsxoCugQQAvD_BwE&gclsrc=aw.ds

 

[DonGray]

Hi there, thanks for all your messages.

A quick update. Basher's suggestion of using the socket worked a treat. Cut into the adjoining section, push the socket in and rivet through. Belt and braces using the solvent weld suggestion.

The holes are causing me a bit of an issue. THe hacksaw trick wasn't successful I'm afraid, probably more down to my skill. Next thing to do is get some steel box section, heat it, and see if i can melt through. THen will try a simple chisel.

Also getting a 16mm drill bit turned down on the lathe at work so it will fit in the hand drill. Drill a 16mm hole, then square the edges off with my trusty fake dremel tool.

The painting i think is sorted now - sand with grey scotch, acetone, adhesion promotor, plastic primer, paint. Just need to find somewhere now where I can buy job lots of sprays!!!!!

THanks for your continuing suggestions!!!

 

[Chuck]

The holes are causing me a bit of an issue. THe hacksaw trick wasn't successful I'm afraid, probably more down to my skill. Next thing to do is get some steel box section, heat it, and see if i can melt through. THen will try a simple chisel.

Maybe use a square sheet metal punch? 19 mm is 3/4 inch:

qmax, q max hole cutters,uk, qmax, q max q-max, qmax hole cutters, q max holesaws

www.knighton-tools.co.uk

I've not personally tried one of these punches on plastic drainpipe but I'm pretty sure they'd work well.

 

[Timmy D]

Haven’t read the whole post but saw you mentioning melting.

Can’t you heat up a bit of 15mm copper pipe and melt through. Will give you a near exact 16mm hole.