Problem with Dicor self leveling lap sealant

kwbush said:

Now, that there is the definitive answer!

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Except that it's wrong, as Molaker pointed out.  What the OP bought was indeed self-leveling lap sealant.

Trivet said:

Except that it's wrong, as Molaker pointed out.  What the OP bought was indeed self-leveling lap sealant.

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Whatever...

Purchased Dicor Self leveling a week ago. Squeezed out of tube nicely but did not self level.  Even applied to a vertical surface and did not run down.  Must of got a bad batch? Will not be purchasing this product again.

There should be a use by date on the tube.  If it is past due take it and your receipt to the seller and get it replaced.  You may have to contact dicor but it is worth a try. 

Hello Guys,
I see more disgruntled customers of Dicor are appearing -  I do not believe that the Dicor product is the problem.
Their self leveling product is what they say it is - self leveling.  Their gun grade product is just that as well, gun grade, (meaning that it is not self leveling.
A number of users have stated that when the self leveling product is extruded, it appears to look like a gun grade sealant (toothpaste consistency), and will not self level.  The reason for this is usually that the sealant is past it shelf life or that it has been extruded from a previously opened cartridge (tube), that has been exposed to air (even though you may have thought it sealed well).  You nay have read that the "life expectancy" of the sealant is 10, 20 or 30 years - this is not the "shelf life".  This is how long the product will perform as intended)  Shelf life is usually 12-24 months.  So do not get confused with that fact.  You are probably asking yourself "What the heck is he talking about, I have to reseal my Dicor every 2-3 years !!"  Before I leave you with the solution to your using sealants, I must add, that when you notice that your self leveling sealant, no longer self levels, IT SHOULD NOT BE USED AS A GUN GRADE SEALANT and should be disposed of as it has outgrown its shelf life and will NEVER CURE, as was intended.

Now, for all of you users, disgruntled or not, PLEASE SEE MY POSTS ON SEALANTS, to help all with their problems.  Do not blame Dicor. if any one deserves blame, it is your RV supplier who is not rotating his sealant stock.  Maybe Dicor should bear some of the responsibility for not stamping a 'best before' date (if they don't), on each cartidge or tube.  My read on Sealants may be a bit dry to some, but it sheds light on your frustrations  and recommendations to solve your problems.  I have also done another post on repairing glass units in some RVs.
Knowledge that I have shared has been accumulated over the past 50 years or so.
Take Care and Enjoy your RVs more.

The RV manufactures have been punishing us with Dicor for decades. Notice how you are required to inspect your roof for cracked Dicor and it pulling back from the intended material to be sealed. If Dicor was a truly quality product, it would not require constant inspection and replacing. But it is some of the cheapest EPDM roof sealer on the market and that's what the RV manufactures go for.
If you want to stop inspecting and resealing your roof all the time, spend the extra money on Sikaflex 221 self leveling EPDM roof sealer. Do it once and be done with it.

Richard

The RV manufactures have been punishing us with Dicor for decades. Notice how you are required to inspect your roof for cracked Dicor and it pulling back from the intended material to be sealed.

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Ummm... NO! All the manufacturers whose instructions I have read simply state that the sealing of the roof has to be inspected bi-annually. There is no mention of a particular product like Dicor. It may be that they do use that product though. Personally, I have had a problem with that particular brand.

It could be true that Dicor may have become sort of a "generic" name for that sort of product though, kind of like  "Kleenex" and "Asprin".

I don't think any caulk lasts forever and it's certainly not Dicor's fault that RV roof seams stretch and twist a lot (some RV brands more than others).  It's the joints that need inspection, not the Dicor.  The Dicor (and similar caulks from other brands) itself lasts many years, probably 10-20 years.  I hold the RV manufacturers responsible for roof problems.

rls7201 said:

The RV manufactures have been punishing us with Dicor for decades. Notice how you are required to inspect your roof for cracked Dicor and it pulling back from the intended material to be sealed. If Dicor was a truly quality product, it would not require constant inspection and replacing. But it is some of the cheapest EPDM roof sealer on the market and that's what the RV manufactures go for.
If you want to stop inspecting and resealing your roof all the time, spend the extra money on Sikaflex 221 self leveling EPDM roof sealer. Do it once and be done with it." 

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First of all, I do give kudos to Sikaflex 221 being an excellent product - unfortunately, last sentence is only partially correct.  It should have been "DO IT RIGHT, THE FIRST TIME AND BE DONE WITH IT FOR SEVERAL YEARS".
Joint design is the number one cause of failure of sealants - including Dicor and Sikaflex 221 and ALL other sealants.  If the joint is not prepared to allow the racking and twisting of your RV, on the road and at your site, along with expansion and contraction of the various substrates that make up the components of your RV, you will continually have the problems of water leaks.  Inspection is the only defense that we have to minimize the problem.  Slapping more sealant or caulk over the existing sealant or caulk, is merely a band aid solution, including Sikaflex 221.  If the old sealant has split, and you feel that it is still adhering very well to the roof, clean the area thoroughly and clean it again and again. using mineral spirits or other cleaning solvent. Now a simple solution is take run a wax candle DIRECTLY over the split, and 1/4" wider on either side of the split, to now have a full 1/2" strip of wax.  That will now be your new joint.  Now, apply your Sikflex 221 or Dicor or Geocel or other Thermoplast Sealants (honestly guys, it really doesn't matter which you choose), over the waxed area and beyond it on either side by another 1/4" - 1/2", giving you a new bead of sealant that is 1" or more wide.  You now have a joint that is 1/2" wide as none of these sealants will adhere or bond to the wax.  So in essence, you have zero adhesion where the old split was and 100% adhesion where the new sealant is applied, giving you a joint that will be able to absorb any movement of your RV Roof Components, including racking, twisting, expansion & contraction.  The aforementioned sealants can absorb movement of 50% and greater.  The simplest way to explain this is - when you merely apply new sealant over the 1/8" split in the old sealant, the joint is 1/8" because you have applied new sealant over the split.  So the new sealant can absorb 50% movement of 1/8" which is only 1/16"; after that the new sealant will fail cohesively because it can now only move the 1/8" plus 1/16", which is only 3/16" total.  Not very big, is it.  If however, you do the wax method, you created a joint which is now 1/2" add your 50% to this joint and you now have a sealant that can absorb movement up to 3/4".  If your joint moves over 3/4", you have more serious problems to address, than just water leaks.  ALL of these Thermoplast sealants get relatively hard after cure, but still retain their elasticity, to enable them to do their intended job, and that is why they are the chosen sealant for the repair.  They can absorb light foot traffic when you are doing your inspection.  Silicone is not recommended.
Please continue to do your inspection, it is your best safe guard against leaks.

Richard



Edit: Moderator fixed misplaced end-quote tag
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Gary RV_Wizard said:

I don't think any caulk lasts forever and it's certainly not Dicor's fault that RV roof seams stretch and twist a lot (some RV brands more than others).  It's the joints that need inspection, not the Dicor.  The Dicor (and similar caulks from other brands) itself lasts many years, probably 10-20 years.  I hold the RV manufacturers responsible for roof problems.

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Gary, your last sentence couldn't be more accurate !!!

Mr. Murphcrud, you last post was spoken like a true Customer Service Representative. We've all see your Dicor crack around sky lights that are not moving around. In fact the sky lights are anchored in a 14" x 14" framed opening. Usually steel or aluminum. So we can take the joint design out of the picture. You speak of doing it right the first time which seem impossible to do with Dicor. Or are you saying all the RV manufactures are incapable of doing it right the first time? As we see Dicor failures on all brands of RVs. You product is not as durable as needed for RV roofs. You product does crack and split from age and UV radiation. Where as Sikaflex 221 does not shrink and will stretch considerable with out breaking and loosing its seal.
I've used both products for repair and reseal over many years and it has always been Dicor that has me up on someones roof in the hot sun trying to fix a leak caused by your produce coming unstuck or cracking. So now I do it right the first time with Sikaflex 221.

rls7201 said:

Mr. Murphcrud, you last post was spoken like a true Customer Service Representative. We've all see your Dicor crack around sky lights that are not moving around. In fact the sky lights are anchored in a 14" x 14" framed opening. Usually steel or aluminum. So we can take the joint design out of the picture. You speak of doing it right the first time which seem impossible to do with Dicor. Or are you saying all the RV manufactures are incapable of doing it right the first time? As we see Dicor failures on all brands of RVs. You product is not as durable as needed for RV roofs. You product does crack and split from age and UV radiation. Where as Sikaflex 221 does not shrink and will stretch considerable with out breaking and loosing its seal.
I've used both products for repair and reseal over many years and it has always been Dicor that has me up on someones roof in the hot sun trying to fix a leak caused by your produce coming unstuck or cracking. So now I do it right the first time with Sikaflex 221.

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Customer Service Representative ????    Never !!!  I am a retired owner of a sealant company that has been "around the horn" many times over and hold no loyalty to any sealant manufacturer.  Let's talk about the sky light anchored in a 14 x 14 framed opening.  You notice that the sealant,  (which is usually not dicor as MOST manufacturers do not use dicor !!  and that's a fact), cracks or splits right at the edge of the sky light itself.  Why ??  Because the joint design is poor.  The plastic butts up against the aluminum or steel, leaving a joint width of virtually nothing (1/16 to 1/8".  So when the sky light flexes, (and they all do), the sealant is put under stress at this very small joint, and it fails cohesively.  If, at the point, where the skylight butts up against the aluminum or steel, a wider joint would have been created, allowing the sealant to be able to move more, failure would have a lot less chance to occur. 
If my interpretation of what you are saying is inaccurate I offer a second possible understanding- if you are saying the skylight is in this metal frame and then screwed or nailed into sawed opening in the roof, we still have a similar situation.  POOR JOINT DESIGN !!  The sealant failure will occur around the perimeter of the steel frame protruding through the sawed opening.  Wood shrinks, and therefore moves more than the metal.  If the joint was made  to insure that the sealant was not butting right up against the wood and metal, the sealant would function as it is intended. 
And, "yes" your sky light does move. when you open it, it moves, when you are motoring down the road, it moves, when you are parked and it is windy, it moves.

You keep referring to 'your product, dicor is not my product.  As I previously stated, dicor is not used by most RV manufacturers as most use the least xpensive thermoplast sealant, that they feel will do the job.  You are lumping all Thermoplast sealants into one - calling all of them Dicor - not true at all.

Now let's talk about Sikaflex 221 - IT DOES SHRINK !!  not much (as it is 95% solids) and the other 5% is solvents, which flash off and is one of the curing mechanisms in this sealant.  If it was 'done right the first time' with proper joint configuration and size, you would not have to be  on anyone's roof applying new sealant.  As I previously stated, most Thermoplast sealants and polyurethane sealants, will do the job ---- including Sikaflex 221 or Sikaflex 1A !!!  Do not apply Sikaflex 221 over the the previously failed sealant without first creating a wider joint using my suggested method or the use of a bond breaker tape.  I'm sure that you are familiar with bond breaker tape, as most professional caulkers are and use it when required.  You are setting yourself up for another failure and remember 'nobody likes to go up on a hot roof' to redo your repair.

Take care and good luck.

Murphcrud is right about non-use of Dicor by many major manufacturers.  Maybe all of the.

I haven't verified the last couple years, but to the best of my Knowledge neither Fleetwood (now Rev Group) nor Winnebago has ever used Dicor sealants, self-leveling or otherwise.  The old Fleetwood Corp used Alpha brand self-leveling lap sealant for rubber roofs and Surebond around skylights. Winnebago has callout sheets available online for sealants on each & every model they make and none I've ever reviewed called for Dicor anywhere.  Since few Winnebagos have rubber roofs, they generally wouldn't need Dicor's EPDM lap sealant anyway. The old Monaco Corp used Acryl-R and Geocel brand sealants, but I'm sure the new Monacos uses whatever the Rev Group factory uses on the other Rev models (including Fleetwood).