Soldering new pipe to old painted pipe

[jaydebruyne]

So,

The story goes like this:

Went to fit a new rad today but plumb centre gave me a double panel instead of a single and because I was in a rush I didn't clock this error. I just stuck it in the van and went to the property.

Anyway, drained the system, put on shiny new valves and hung the rad to find out that the tails are 20mm out to the pipes. So I bend myself 2 20mm offsets (first time by sight and spot on might I add, quite proud of that!) and look at the pipe and it's screaming at me "solder me and I'll swear I'll leak!".

I know I can put some heat on the paint and scour it off with some wire wool. But is it really alright to solder???? Would a compression coupling be better??

I didn't finish the pipework in the end as it got late and the tenant needed to go out. But I'm going back on wednesday to finish it off.

So I'm asking for a few tips regarding soldering old pipe to new, or if compression couplings would be better?

Cheers

 

[jaydebruyne]

Use map gas on old pipe if it still has a bit ov water in it

I use mapp. But I've tried soldering with water in pipe and it doesn't solder well :/ how do you do it?

 

[antdad]

With Mapp you can burn a hole through the pipe until the water comes out, then solder away.

 

[Matt06]

i use sanding mesh from stoolstation , if that doesnt do it then knife / grips with heat

the suck water out with either wet vac or syphon pump thing

 

[jaydebruyne]

i use sanding mesh from stoolstation , if that doesnt do it then knife / grips with heat

the suck water out with either wet vac or syphon pump thing

Oh ok, yeah I use my wet vac to suck out the water, but I find for some reason the pipe keeps filling - patience was never a virtue of mine

 

[Matt06]

works better if you open pipe somewhere else ie if you had a length of pipe capped 1 end, vacuuming the other end undo/take off cap to let air in

 

[jaydebruyne]

works better if you open pipe somewhere else ie if you had a length of pipe capped 1 end, vacuuming the other end undo/take off cap to let air in

Don't the bleed valves on rads do the same thing?

 

[Matt06]

If pipe is open more air gets in , so water clears faster i find anyway

Also put the vac hose over the pipe then block the vac hose with hand or a rag so it just sucks through the pipe
Don't know if you do that already or not

 

[jam1979]

I use mapp. But I've tried soldering with water in pipe and it doesn't solder well :/ how do you do it?

The pipe can't be full of water but if there's a bit in turn your lamp on full pap and plenty of flux

 

[AWheating]

any method of removing the paint will be fine. If its not to close to finished surface then use a torch to help ther paint peel/ loosen. A scraper, pair of grips or whatever to remove the major amount of paint then a abrasive to clean the metal surface. Wipe the pipe clean with a damp cloth and solder as normal.

If the pipework is full of water then a wet vac is prob the easiest and cleanest method to remove that last bit of wata. For some reason these job always seem on cream carpet.

use the flux your comfortable with, if you want to try another flux do so on fittings that are easier to replace/ fix on a less important job.

 

[drip-dry]

i just usually put at bit of wire wool between my buttockd,sit on the pipe and turn the music up loud on the radio..If you are tuned to rock fm ...you will find cleaned in no time..classic fm can drag it out a bit though....

:45:

 

[jaydebruyne]

any method of removing the paint will be fine. If its not to close to finished surface then use a torch to help ther paint peel/ loosen. A scraper, pair of grips or whatever to remove the major amount of paint then a abrasive to clean the metal surface. Wipe the pipe clean with a damp cloth and solder as normal.

If the pipework is full of water then a wet vac is prob the easiest and cleanest method to remove that last bit of wata. For some reason these job always seem on cream carpet.

use the flux your comfortable with, if you want to try another flux do so on fittings that are easier to replace/ fix on a less important job.

Thanks AW heating.. I'm having to cut quite close to the floor so I'm a little nervous about getting it wrong! But I'll take my time to make sure it goes ok

 

[PriestyUK]

Little tip:

If you have a pipe that you've cut into that runs vertically, say a pipe coming out of a floor to a rad and it still has abit of water in that can't be drained out. Grab a cleaning product bottle you know the ones that have a spray nozzle on them. Slide that down into the pipe and spray till theres nothing left. Then you can solder away

 

[drip-dry]

or one of these

Draper 18937 Drill-Powered Pump: Amazon.co.uk: DIY & Tools

handy little tool

 

[jam1979]

Then you've got spray all over mr blogs cream carpet or wall aha