Re-Adhering kitchen sink to crumbling countertop

[shardy]

Hi,


My kitchen sink is installed in a very old (~25 years) countertop which is not in the best of shape. The back of the sink is no longer securely attached to the countertop because the "wood" in the counter is soft and crumbling (a leak around the base of the faucet allowed water to get underneath the lip of the sink and destroy the counter). I caulked the lip of the sink to prevent any further water from entering that area (I also fixed the faucet leak).

I'm wondering if anyone else has had a similar issue of trying to adhere a sink to a less-than-pristine countertop and if you have any ideas of how best to re-adhere it. I was thinking of injecting some construction adhesive under the lip, but that would make it almost impossible to remove the sink in the future. Any other ideas?

Thank you in advance to anyone that can offer any suggestions.

 

[inspectorD]

Go get yourself some adheasive caulking, phenoseal works just fine for the repair you need to do, and it can be cut out later when you change the top.

 

[Nestor_Kelebay]

If the particle board is swollen, I would paint the edge of the hole cut in the counter top (and the underside of the counter top around the sink) with boiled linseed oil to prevent further absorbtion of water and deterioration.

After that, I would just use plumber's putty under the lip of the sink to keep water outta that joint.

Plumber's putty is thick enough to allow a good 1/2 inch height difference between one end of the sink and the other. Just roll the plumber's putty between the palms of your hands, and press it down onto the counter top under where the lip of the sink will be.

I recommend using boiled linseed oil instead of oil based paint here because boiled linseed oil penetrates into dry wood MUCH BETTER than an alkyd paint will. That's because alkyd paint resins are absolutely TINY compared to latex paint resins, but they're still HUGE compared to boiled linseed oil MOLECULES. So, those boiled linseed oil molecules will penetrate deep into the particle board wood and cure by auto-oxidation to waterproof both the wood that's in good condition AND the swollen wood. About the only other thing that would work in a similar way would be a liquid epoxy meant for painting onto (or injecting into) rotted wood. You could paint a liquid epoxy onto the swollen wood to consolidate and water proof it, but linseed oil would do the same job equally well, but be more "user-friendly" than an epoxy.

 

[inspectorD]

If you use Boiled linseed oil...make sure you dispose of the wrags properly, or you will burn the place up. Folks sometimes need a reminder of this because they will spontaneously combust.
And the problem with plumbers putty is ,it is not an adheasive like you asked about, but it still may work for what you are doing.
Good luck with your counter.

 

[Nestor_Kelebay]

The real problem is that when this counter top was installed, no one waterproofed the exposed particle board that might get wet.

Whenever I install a laminate counter top, I paint the edges of the holes I cut for the faucet and sink and I paint the underside of the counter top for a good 6 inches all around the sink and taps. Or, as mentioned in my previous post, boiled linseed oil or liquid epoxy (of the kind used for consolidating rotted wood) can also be used. The epoxy would be the most durable waterproofing material.

People that install plastic laminate counter tops will never go to the trouble of doing this... ...unless they're installing the counter top in their own house.

PS:
What InspectorD is saying is very real. Drying oils like linseed oil or Tung oil, alkyd paints and alkyd based polyurethanes all cure by a process called "auto-oxidation" whereby oxygen (O2) molecules in the air separate and form a pair of C-O-C crosslinks wherever there are two unsaturated sites in close proximity. As more and more of those crosslinks form in various spots throughout the paint film, it behaves less and less like a liquid, and more and more like a solid.

Keep in mind, however, that the auto-oxidation process is EXOthermic, which means that it releases heat. So, in order for a pile of rags damp with boiled linseed oil to burst into flames, you need two things:
1. For oxygen to be able to get to the oily rags for that auto-oxidation reaction to occur, and
2. For the rags to be insulated (even by themselves) so that the heat generated accumulates and that the temperature inside the pile of rags continues to increase (to the kindling point of cotton).

If you do anything to prevent either of those conditions from occuring, you eliminate the risk of a fire. So, if you were to scatter the rags out on an old newspaper so they weren't in a pile, then the heat generated by each rag would dissipate, and no fire would start. If you were to clean the rags with a liquid dish washing detergent, then that would emulsify the linseed oil, and prevent it from coming into contact with oxygen, and that would also prevent a fire. (linseed oil is a vegetable oil just like corn oil or olive oil, and liquid dish washing detergent will cut through linseed oil based paint or Tung oil based varnish just as effectively as it cuts through any cooking oil like corn oil or olive oil)

The officially "recommended" way of disposing of rags damp with linseed oil (or any drying oil) is to fill a paint can with water, deposit the rags in that can, pound the lid on tight, and leave the can in your garbage. That's what I understand to be the "correct" way to dispose of painting waste, but I think it would be best to take the label off the can because both oil based and latex paints are now considered "hazardous waste" and have to be taken to a hazardous waste depot.

 

[shardy]

Thank you to everyone for your recommendations, they are very helpful. I think I will give the plumbers putty a shot since we are planning on replacing the countertop within the next 9-12 months (hopefully). I'll also use the linseed oil idea as well to shore up the countertop a bit. I'm actually a Physicist by trade, so, I'm well aware of the need to take care of soiled rags; I have a flammables container for disposing of solvent-soaked objects in my lab, so, I'll just transport them there. Thanks again everyone, this was extremely helpful!

 

[inspectorD]

Glad we could help....and we have our own physicist in Nestor, so Im just here to lend some reality once and a while... so he can explain it to folks after I do the damage. Thanks Nestor.