Recomended Caulking

[Sprint54]

Well that didn't take as long as I expected. Just removed some of the cover tension springs and pulled the pool cover back from a corner to get a peek for the camera. I believe it's caulking. The gap is about 1/4" at the minimum to 1/2" in some spots. It's not grout, like the tile grout, as I can stick a finger nail partially into it, it's chalky and has some flexibility to it. I've attached two pictures for reference. Let me know what you think. Thanks
Scott

[KurtV]

I think you're right that it's caulking. I don't know enough about that to make a recommendation.

[duraleigh]

Hi, Scott,

(nice pics...thanks) (nice coping, too...I like that look)

Pretty sure that's acrylic caulk (acrylic shrinks). Too bad they used such nice coping material and short changed on the caulk.

Anyway, I believe your course of action is to remove the old caulk and replace it with a high quality polyurethane caulk. Removing the old is probably going to be 75% of the work. I'd start on a small section and get your system perfected start to finish.

Once you get the section cleaned out...doesn't have to be perfect...be sure to use masking tape on both top and bottom of the new caulk line. I have had very good success with a caulk named Vulkem 911. Comes in many colors and not too much money...about 3.25/tube, I think.

Again, the poly is tough to work with (not water soluable) and takes days to dry out but you'll never have to replace it again.

Dave S.

[Sprint54]

Thanks Dave. Spent 5 minutes searching the Web for Vulkem 911 and get several hits but have not found a site that sells it. Any idea where I can get this stuff? Also, replacing the caulking is just one of many items on my spring startup list for the pool. The list includes, pool caulking (which this is about), acid washing pool, replace pump seals and replace pool decking caulk (the stuff you walk on). Since I'm doing all this, I'm just wondering about your comment, 'nice coping, to bad they used caulking'. If I am going to remove the caulking and drain the pool, is there another choice that would be better? Hate to go through all this and find out later that I could have had xx but I settled for yy. You know what I mean? The extra work I'm not worried about and if the xx is only a few more dollars but better for the long run and aesthetics, why not do xx. Anyway, your thoughts and help are appreciated. Thanks Scott

[duraleigh]

Hi, Scott,

I misled you a little on that post. I should've said "too bad they used acrylic caulk instead of polyurethane caulk" You must have a flexible seal at that point because the pool vertical wall and the coping move independently of each other...not much, but they move. If you try to grout it, it will crack before you know it and possibly fall out if your temps are extreme enough.

I suspect they used acrylic caulk on your expansion joints on the decking as well. Again my advice would be to switch to poly when you get the old cleaned out. The depth of the caulk should roughly equal the width of the gap you're filling. Masking tape on each side of the joint is mandatory.

I got that Vulkem stuff at a local (I don't think they're a chain) industrial supply house that specializes in masonry accessories. Drains, waterproofing, etc. It's called "General Materials" The Vulkem is made by a company called Tremco. I'm sure there are others just as good but this one works so well for me, I've never attempted anything else. I hope you are able to locate it but, if not, talk with some concrete pros in your area and ask them what they use to seal expansion joints.

Dave S.

[Sprint54]

Thanks Dave.. Going to Reno on Friday and have some concrete supply stores to call on. Appreciate your help.

Kind Regards,
Scott

[waterweasel]

You might want to look at Vulkem #116 instead. The same colors as the #911are available, but #116 is suitable for continual immersion. I work for a company that sells Tremco products for the concrete industry, and we sell tons of the stuff to the pool builders in my area (Oklahoma City). If you go to Tremco's website you can find a dealer in your area. Out of all the different polyurethane sealants we sell, #116 is the only one I would use in your situation. It is probably around $0.50 per tube more, but worth it. Great product.... (by the way this is not a sales pitch)

[Sprint54]

Hi Dave, couldn't find Vulkem 911 in Reno on Friday but did find an equivalent. "Sikaflex 1a" Polyurethane sealant". Has all the same properties and performance as Vulkem 911. Now for the million dollar question. Is there a trade secret for removing the old polyurethane sealant? Over the weekend I have tried using a sharp utility knife, a high speed burr, chemical softening agents, other tools that will not be named and bad language, nothing penetrates this old stuff. I have searched the Internet and found solutions that involve heating and scraping the caulk, cutting the two edges with a special diamond blade ten pulling the caulk out, and more chemicals that are suppose to soften the old caulk. What am I missing? Thanks.

Kind Regards,
Scott

[duraleigh]

Hi, Scott,

I simply do not have a good answer. I've only installed it...never removed it. I can imagine it is a real pain trying to get it out of there.

Scott you might try johnbridge.com. It's a forum much like this one but for ceramic tile. Lots of really knowledgeable guys on there and they may have a good answer. If so, I hope you'll post back and let me know, too.