Thread: Bonding PVC Pipe

The solvent mix in PVC cement is every bit as toxic as acetone, if not moreso.
Realistically, how much do you need to use and for how long? 5 minutes with the door open?

Dry fit everything. Mark the registration of the pieces with a grease pencil. Slop in the PVC cement
and assemble 1/4 turn from final, count to 10 and twist = done.

The commercial process involves resistance welding: wrap one pipe with a thin paper tape containing a very thin copper "resistance wire." Attach the DC power leads, set the timer and wait. Power off and cut the protruding res wire ends. The two PVC pipes are physically melted together.

Hot glue might be OK but it chills & sets with very little working time.
Possibly a bead around the finished joint. Glue sticks last for decades, they are no more than
low temp, thermosetting plastic. I did theatrical F/X for 20 years;: masks, props, costumes, etc.
Not unusual to have 4 glue guns hot at the same time, 4 colors. Guns from 150W commercial
to dinky little craft guns. I built prototypes from cardboard & hot glue, then cut that up as patterns for products made of foam rubber, riveted aluminum sheet, etc.

The size, the capacity, depends on the volume of melt that you expect to express from the melt chamber
in the gun in one big squeeze.

Originally Posted by Robson Valley

The solvent mix in PVC cement is every bit as toxic as acetone, if not moreso.
Realistically, how much do you need to use and for how long? 5 minutes with the door open?.

I agree,exposure during working will be low.

I decided to look up the MSDS for acetone and PVC cement, the main component of which is butanone and it turns out that neither are that toxic and neither are classed by the US EPA as a hazardous air pollutants.

In terms of breathing toxicity, acetone is slightly less toxic than butanone but acetone is more volatile so exposure at room temperature will be greater.
By way of comparison both acetone and butanone have a breathing toxicity somewhere between methanol (lower) and ethanol (higher) - it might make you think about sniffing your whiskey too hard!

PVC cement also contains other "stuff" like hexanone and tetrahydrofuran.
Both have breathing toxicity levels similar to ethyl alcohol, but like Butanone they have higher boiling points than acetone so exposure at room temperature will be lower.

So nothing to worry about.

Originally Posted by pjt

I wonder how you would go if you cut a smaller hole in the 150 then heated the area around the hole (hot air gun or similliar) then pushed thru a piece of the 100 (ideally from inside the 150) this might form a bit of lap to give a bit of mechanical strength to the joint


Pete

That's exactly what I did to make this three way junction. The smaller pipes had a flange formed on the end. The undersize hole in the larger pipe was heated with a heat gun and the smaller pipe forced through from inside and pulled out until the flange inside the bigger pipe was a reasonably smooth fit. The pieces were fastened together with short self tappers and sealed with silicon.

Originally Posted by pjt

I wonder how you would go if you cut a smaller hole in the 150 then heated the area around the hole (hot air gun or similliar) then pushed thru a piece of the 100 (ideally from inside the 150) this might form a bit of lap to give a bit of mechanical strength to the joint
Pete

That's how I do mine as well.

I cut the 100 mm piece first so that it sits neatly on the 150 mm.
Put the 100 mm onto the 150 in the position where I want it and trace around it.
Cut the hole in the 150 about 2 mm smaller than the hole.
Heat the edges of the hole and force the 100 mm pipe through.
Keep applying low heat and pull the 150 mm lip back the other way.
I then plastic weld the join but any sealant or thick adhesive will work.

Appreciate the suggestions.

I decided to go the heated glue gun route today after trying it out on a couple test pieces left for a couple days to fully set. After applying the glue via the gun I used the heat gun to remelt the bond which helped fill the gaps and smooth the rough edges of the glue job. I have undercut the 150mm by about 3mm, pipe wall thickness as the 100mm pipe. So, if the glue job doesn't work I'll heat it up and try your suggestions of pushing the 100mm through the undersized hole cut in the 150mm pipe.

Thanks again.

Gareth