Originally Posted by wrvond
When I installed a vent cover on my Alpha Systems roof I used Dicor to seal it thinking it was the same stuff as Alpha Systems sealant. The Dicor caused the TPO to blister where it made contact so I would say it’s not the same stuff.
If you have the Alpha Systems roof, stick with their recommended product.
DICOR markets two types of "self leveling sealant". The older, most readily available type is 551LSW (white) and has the "standard dispersant mixture" (petroleum agents to aid in application flow). https://dicorproducts.com/product/no...-lap-sealants/
The "new and improved sealant" is 610SASLW-1 and marked as "ultra sealant". It contains no solvents or isocyanates. https://dicorproducts.com/product/se...ultra-sealant/
It's the solvent mixture that caused your bubbling, not the "name brand"...
A bit of "history"... DICOR first introduced the EPDM membrane to the RV market, and they were the only producer for a number of years. Then Alpha Systems introduced the TPO membrane and it became the "industry standard" replacing the EPDM type membrane because it was cheaper and weighed less along with other improvements over EPDM.
When TPO first came out, Alpha Systems recommended DICOR sealants for maintenance and resealing. Then, after a couple of years, they started marketing their own line of sealants and "suddenly" DICOR was a no-no.... Ironically, DICOR was "OK to use" until their own products showed up on the market. Now, with the "high solvent sealant for EPDM" and the "Low Voc sealant for TPO" both Alpha Systems and DICOR market the correct sealant mixtures for TPO roofing.
In your issue, it was the "wrong type DICOR sealant" that caused the bubbling, not the brand name.... DICOR Ultra Self Leveling sealant will not cause any TPO softening, just like Alpha Systems brand.
Here's a good article on "RV Roof Sealants": https://dicorproducts.com/eblast/DP-133/a1/
It addresses the "softening and rippling of TPO when using the "standard solvent sealants".