Installing P trap for the first time..chrome or plastic?

**Andrew21** · 08-23-2008, 10:13 PM

Hey all,
Just got my undermount sink in and now I need to hook everything up to the sink (faucet, p trap, etc). This is the first time I will ever do something like this and I'm not that clueless but somewhat lost.

Should I use the chrome or the plastic piping? I would like a nice look under the sink. I know, I know, nobody really looks under there but I would gather it would look nice. If the plastic is the best and easiest way to do it, I'll go with that.

Now the drain pipe is coming out 9 inches. WOuld I have to cut this? If putting in the chrome pipe, do I need to solder the connections? Thanks!

**jimbo** · 08-24-2008, 06:45 AM

Under a cabinet, I don't think appearance is an issue. Plastic probably has an edge in longevity...as in foever, whereas a brass trap will corrode ...eventually.... A brass, or chrome plated, probably has a higher success rate of not leaking at initial install. Plastic can sometimes cause a problem, as you can only tighten the nuts so tight. I usually replace the nylon gaskets with rubber ones, coating them lightly with plumbers grease. These seem to seal up better.

If you are in MA, or some other states, you will be required to solder the trap arm to your waste stub. If your code allows it, I would cut that stub closer to the wall, solder on a slip joint trap adapter ( sometimes called a Desanko fitting).

**nhmaster** · 08-24-2008, 09:13 AM

short of using a rubber fernco which would be savage, a desanko or trap adaptor fitting will have to soldered on.

**kingsotall** · 08-24-2008, 09:54 AM

And it's going to take some considerable amount of heat to solder to that copper pipe. Just letting you know...

**Andrew21** · 08-25-2008, 02:34 PM

Originally Posted by nhmaster

short of using a rubber fernco which would be savage, a desanko or trap adaptor fitting will have to soldered on.

What is a desanko adapter? Is that a copper fitting that when I solder it on, there's a thread at the end? I went to Lowes to get some parts but I didn't know 2 things.

1. There are different sizes of pipes, 1 1/2, and 1 1/4.
2. I took out a strainer and started to use the parts to put everything together in the aisle! LOL. As long as I know what to buy, I'll be good. But the last thing is that adapter.

**Redwood** · 08-25-2008, 04:08 PM

Do you know how to sweat copper pipe?

**Andrew21** · 08-25-2008, 06:00 PM

Originally Posted by Redwood

Do you know how to sweat copper pipe?

Yup! Thats not a problem.

**Redwood** · 08-25-2008, 06:13 PM

This would be the ticket if that is a 1 1/2" pipe. Measure the O.D.
http://doitbest.com/Copper+Unions-El...sku-431063.dib

**Andrew21** · 08-25-2008, 06:19 PM

Sweet! Thanks! Let me see if its across the street at HD...i doubt it though.. will report back

btw, what does DWV mean?

**Redwood** · 08-25-2008, 06:22 PM

Drain waste vent.

**Andrew21** · 08-25-2008, 06:52 PM

thanks. Of course they didn't have it at HD. Its the worst there. Fittings and stuff all over the place. Time to take a trip to Lowes or the local supply store.

They did have it in the PVC section though. But I wouldn't know how to connect it to the copper if I did get the piece.

Thanks Redwood!

**Redwood** · 08-25-2008, 07:11 PM

PVC is tough to solder!
The route you're going is better.

**Andrew21** · 08-25-2008, 07:12 PM

I know! LOL. anyway, gotta run to the other store. Will keep you posted.

**Andrew21** · 09-14-2008, 02:31 PM

Ok, i'm back. Was tied up doing other things but here's my plan. Hopefully I'm doing this correct.

I'm going to cut the waste pipe closer to the wall to install a 45 degree angle street elbow and then put on the trap adapter fitting as pictured before. Then sweat the fittings on and connect the rest. The sink drain is not aligned behind the waste pipe. Sorry for the angled shot. Here's what I'm up to now..

I just took a picture of this to see if the fittings fit...