Maintenance Caulking

[ELeland]

I need to recaulk a few areas of the exterior walls and caps on my coach.  Dicor and Proflex RV have been recommended here but are very limited to available colors.  I would like to match the main body color which is mainly silver.  I found this product (SONNEBORN 1025616 One Part Urethane NP1 Sealant, Aluminum Gray).  I have used Sonneborn products with great success in the construction industry for years.  This comes in "Aluminum grey" color which may be a better color match than plain grey.  The PO used a very dark color, almost black in some areas. 

Any opinions on this product?

https://www.amazon.com/SONNEBORN-1025616-Urethane-Sealant-Aluminum/dp/B00AGZ0428/ref=sr_1_1?s=hi&ie=UTF8&qid=1536539228&sr=1-1&keywords=SONNEBORN+1025616+One+Part+Urethane+NP1+Sealant%2C+Aluminum+Gray

Thanks,
Ed

 

[darsben]

I read the specs and the product is xylene based. I wonder about effect on paint/decals

 

[Jkoht]

What about grey butyl tape?

 

[ELeland]

What about grey butyl tape?

I only need to dig out a portion of the old caulking that is cracking or pulling away and apply a small bead to replace it.  The butyl tape is too wide for this application. The tape would be OK on the end caps at the roof level though.

If the Sonneborn is OK to use, I wonder how easy it is to dig out when it's time to recaulk?  Some of the reviews says its very sticky and permanent. Maybe that is good.

 

[Gary RV_Wizard]

You can get the gray Geocel Proflex on Amazon.
https://www.amazon.com/Geocel-26102-Tripolymer-Sealant-Cartridge/dp/B000DZBHAE

I see no reason not to use the Sonneborn product on side seams, but don't know enough about it for the roof cap application. That seam is subject to high-stretch, plus it adjoins the roof membrane.  If the roof is EPDM, you want an EPDM-compatible sealant.  Note that Geocel Proflex isn't recommended for contact with EPDM either. If TPO or fiberglass or metal roof, either the Sonneborn or Geocel should be ok as far as compatibility.  The Dicor is very stretchy, it's chief advantage.

If the only cap seam you are sealing is on the sides rather than the roof, any of those products is probably fine.

 

[ELeland]

Thanks for the replies.  It is a fiberglass roof and the side seam aesthetics is important to me.  All else being equal, I think I'll get a tube of each and use the best color match.  What's not used on the exposed areas can be used in an inconspicuous area so I don't waste it.

Thanks,
Ed

 

[ELeland]

  The PO used a very dark color, almost black in some areas. 

Update - I figured out why the old caulking looked "almost black".  The PO had used clear silicone and it had degraded to a point where moisture had gotten behind it and was growing mold underneath.  I'm surprised there had been no water intrusion. The old caulking pulled out like a string since it had lost most of it's adhesiveness.  Start to finish was maybe 4 hours, most was prepping once the old caulk was removed. 

The horizontal joints have been recaulked and look awesome now that they match the main body color.  I ran out of material and will tackle the narrower vertical seams later.  They appear to have the same silicone material.

Ed

 

[Gary RV_Wizard]

Sounds like you have it under control!

 

[Murphcrud]

Update - I figured out why the old caulking looked "almost black".  The PO had used clear silicone and it had degraded to a point where moisture had gotten behind it and was growing mold underneath.  I'm surprised there had been no water intrusion. The old caulking pulled out like a string since it had lost most of it's adhesiveness.  Start to finish was maybe 4 hours, most was prepping once the old caulk was removed. 

The horizontal joints have been recaulked and look awesome now that they match the main body color.  I ran out of material and will tackle the narrower vertical seams later.  They appear to have the same silicone material.



Ed

Whoaaaaa, Slow Down. 

I hope that the sealant that you removed was NOT silicone.  If it was, you might now be in a situation that you might regret down the road.  Where silicone has been used previously, only silicone should be used when replacing the failed silicone sealant.  It may appear that the new sonneborn sealant that you have used is sticking well.  I can assure you, it probably isn't.  Silicone, ALWAYS leaves a trace of silicone fluid, after it has been removed and nothing will permanently bond to that 'cleaned surface' other than silicone.  There is a silicone remover manufactured by Dow Corning, that will remove all traces of old silicone, which will then allow you to caulk the joint with other sealants, including the Sonneborn product that you prefer.
If you have any other questions on your application and require additional info,you can PM or email me.

Harv

 

[ELeland]

Whoaaaaa, Slow Down. 

I hope that the sealant that you removed was NOT silicone.  If it was, you might now be in a situation that you might regret down the road.  Where silicone has been used previously, only silicone should be used when replacing the failed silicone sealant.  It may appear that the new sonneborn sealant that you have used is sticking well.  I can assure you, it probably isn't.  Silicone, ALWAYS leaves a trace of silicone fluid, after it has been removed and nothing will permanently bond to that 'cleaned surface' other than silicone.  There is a silicone remover manufactured by Dow Corning, that will remove all traces of old silicone, which will then allow you to caulk the joint with other sealants, including the Sonneborn product that you prefer.
If you have any other questions on your application and require additional info,you can PM or email me.

Harv

Thanks for the heads up Harv - It definitely was silicone.  I cleaned the joint with xylene after removal if that makes any difference.  Now that the Sonneborne has set up I can check to see how well it bonded.  If it is lacking bond, it should be fairly easy to remove and then I can use the Dow product you mention.  Maybe the first time was just a practice run

 

[Gary RV_Wizard]

I hope that the sealant that you removed was NOT silicone.  If it was, you might now be in a situation that you might regret down the road.  Where silicone has been used previously, only silicone should be used when replacing the failed silicone sealant.  It may appear that the new sonneborn sealant that you have used is sticking well.  I can assure you, it probably isn't.  Silicone, ALWAYS leaves a trace of silicone fluid, after it has been removed and nothing will permanently bond to that 'cleaned surface' other than silicone.  There is a silicone remover manufactured by Dow Corning, that will remove all traces of old silicone, which will then allow you to caulk the joint with other sealants, including the Sonneborn product that you prefer.

My silicone experience hasn't been as bad a murphcrud's apparently was.  Silicone does leave a residue and it can be problematic, but I've removed it with both the commercial silicone removers and simple mineral spirits.  Just don't skimp on the clean-up task.  Silicone cleans off well enough if the surface is a hard finish (painted, gel coat, tile or metal), and porous surfaces aren't bad either, perhaps because the residue sinks in enough that the bonding surface is clean. 

I don't know where EPDM fits on that scale, though. I've never had to remove silicone caulk from a rubber roof.  However, I don't think EPDM is involved in ELeleand's rig.

 

[Murphcrud]

My silicone experience hasn't been as bad a murphcrud's apparently was.  Silicone does leave a residue and it can be problematic, but I've removed it with both the commercial silicone removers and simple mineral spirits.  Just don't skimp on the clean-up task.  Silicone cleans off well enough if the surface is a hard finish (painted, gel coat, tile or metal), and porous surfaces aren't bad either, perhaps because the residue sinks in enough that the bonding surface is clean. 

I don't know where EPDM fits on that scale, though. I've never had to remove silicone caulk from a rubber roof.  However, I don't think EPDM is involved in ELeleand's rig.

This post is more accurate that the one where you stated "Looks like you have everything under control".  I'm sure the poster felt that he was doing the right thing--- Not !

 

[Murphcrud]

Thanks for the heads up Harv - It definitely was silicone.  I cleaned the joint with xylene after removal if that makes any difference.  Now that the Sonneborne has set up I can check to see how well it bonded.  If it is lacking bond, it should be fairly easy to remove and then I can use the Dow product you mention.  Maybe the first time was just a practice run

I would definitely keep a close eye on it.  If you applied the Sonneborn beyond the removed silicone sightline, your bond should remain intact.  If not - good luck.

 

[blw2]

yeah, my experience is that even silicone won't stick where there was once silicone.

lots of iterations of mineral spirits, scraping, mineral spirits scrubbing, repeat, repeat should take it off in my limited experience.  Hard work.

I'm fairly sure about the only silicone joints I've seen last a reasonable amount of time without failure were the corners of a mass produced fish tank, and the RTV sealed mating surfaces in engines/machinery....both very specialized applications.... and specialized products too, I'd guess.