How to seal around copper pipes without compromising them

[uhmorphous]

Hi all,

I have a deep kitchen cupboard original to the 1950s home that has a huge hole where the h/c copper pipes come in for the kitchen sink. I need to critter/bug-proof it and have gotten as far as a wall board cutout glued. But the remaining gap to the wall is still too large for anything like expanding foam.

I want to make sure I'm sealing this area without compromising the pipes. Any suggestions are welcome and appreciated. Thanks.

Two photos (one shows weights, which were just used to apply pressure while glue was setting) attached.

 

[MarineBob]

I would stuff a big old wad of fiberglass insulation into the cavity. If its stuffed tight I don't think any animals or bugs would get through. Just a thought, instead of having your relief cut towards the back wall, put your piece with the cut out towards the right, that might leave a smaller hole to fill. One more thought. Might want to consider finding a surplus piece of vinyl flooring to gut to fit under the sink, Might give a nice lining that is water proof and looks good. Would not leave a hump where the pipe cut outs are also. Before that you could stuff the hole with fiberglass. Anyway, a couple of ideas that are easy to do. If you do the vinyl sheet idea, might find some at the big box stores or a local flooring guy has a small piece for the cost of good will. Make a pattern out of something easy to work with first for the vinyl.

 

[uhmorphous]

I'm embarrassed to say I haven't finished this project, so your response is very timely Thanks, Bob.

 

[MarineBob]

Just saw the slide rule. Antiques these days. Showed mine to a couple of kids. No idea what it was

 

[uhmorphous]

I still have it in the original sleeve. It was my dad's. Coolest thing ever lol

 

[MarineBob]

In my college days, this is the tool we used. When I was a senior, calculators were starting to become available. Only the rich kids could afford them. I knew my time was done when I saw a newbie with a slide rule on this belt, right side and on the other side, a belt mounted calculator. Prepared for any circumstance

 

[uhmorphous]

Well, I'm embarrassed to admit I just got up enough courage to use the spray foam on this project. I made an unholy mess of it (it's difficult to get to and then to angle, and I'll admit my gloved hands were shaking already because I'm so frickin' terrified of this product due to its... well, everything on the warning label). So, I turned off the furnace, opened windows (this is inside a floor-level cupboard so don't even know... anyway)...

I was going to do dishes, and realized I sprayed this around the hot and cold pipes that go to the kitchen sink, but in a cupboard next to the sink (approximately 2-3 foot pipe length from the sink, if not more).

Because of the heat/cold restrictions of this product (expanding spray foam), should I avoid using hot water until it's cured? Will it explode or catch fire or something? Also application temp range is 60-90f and if the pipe (which the badly sprayed foam is touching).

I've been avoiding this project because of my extreme reservations about the spray foam stuff, but I don' have the skills to complete alternative suggestions made here and on another site. (I tried stuffing some fine steel wool but the hole is too deep and it kept falling through.)

Good grief. Any thoughts welcome.

(Oh, and it's Great Stuff Gaps & Cracks insulating foam sealant for up to 1")

 

[MarineBob]

I've used the spray insulation stuff for all sorts of things. I got to admit I read instructions only after something goes south, so pretty rarely. Only issue I have had is long ago, I squeezed a window from too much when it expanded. I think there is some foam now that is used for fire block so while I doubt its fire proof, it is made to seal up wall cutouts to prevent fire from going up inside walls. It might not be as expanding as some of the other versions.

 

[uhmorphous]

Thanks, Bob. I know I'm being too cautious, I think because of complete lack of familiarity and experience with these kinds of products. I'm still too wary about using the hot water. Tomorrow, I'll get a mirror back there and make sure I actually sealed everything. It is so frickin' funny lying on the floor on my side trying to stretch my short little arm back in there.

I've dug post holes, raised barns, felled (dead) trees and skidded logs, built a kayak, re-edged all kinds of blades, steamed and shaped wood for snowshoes, helped build residential sound studios, changed my own oil, did odd fix-it jobs, and restored hardwood floors in our old flat. My husband loved cooking and cleaning, so we made a good team.

I'm trying to figure out when, exactly, I became such a wuss.

I'm blaming it on living in the city.