Why do so many use Dicor lap sealant when other products are far superior?

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Jack Grit

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Hi folks, I am in the process of sealing the roof of my Toyota Horizon. I watched quite a few videos on YouTube suggesting using Dicor self leveling lap sealant. Winter is at hand so I pulled the trigger and bought four tubes from Amazon. After delving deeper into the subject, the people that use Dicor (self leveling or not) suggest checking it twice a year for cracks. Seems Dicor cracks often. Sooner or later one has layer after layer  of Dicor on their roof. Can anyone explain why Dicor is so popular? Am I missing something? I am considering giving the Dicor away and purchasing a much better sealant. Probably something from 3M used on boats. If I make it to the RTR, I will likely give it to someone who already has Dicor on their roof as it appears to work well on cracked Dicor.
 
I've often wondered about that too. Everything made for use on boats is better than what you'll find at RV supply stores. I think people buy Dicor because RV dealers recommend it and it's sold specifically for RVs so they just kind of blindly use it.

Before buying anything for your RV check boat supply outlets, hardware stores, and even Walmart. Prices and quality are often better. If you can't find a part at a regular store try a small RV supply store which will usually be cheaper than Camping World.

How's your roof coming along? I'm hoping that you didn't find any silicon caulk up there - should be outlawed. :-D
 
I buy dicor because it works. Cracks have not been a problem.
 
Most comercially bult RV's are designed to fail it seems as cheaper built means more profit. Most people that buy RV's don't want to pay what it would cost to build one that would last. RV manufacturers that want to make a profit have to attempt to build a product that will give them the most sales. A boat or airplane manufacturer couldn't sell a boat that wouldn't float or a plane that wouldn't fly but an RV manufacturer can sell an RV that requires yearly maintenance to keep it from leaking because people who buy them rarely use them and won't pay the price for one built to last.
 
The 3m boat sealants you're referring to are urethane adhesives. They work great, but are almost impossible to remove if you should ever need tip disassemble the parts. Geocell tripolymer roof sealant works well and is available at any hardware storea or home depot.
 
3M 5200 yes, meant to be permanent, need a chisel to remove.

4200 not so much, stays very flexible, can take it off when needs rebedding, also Sika 291.

Anything's better than sillycone
 
Dicor seals extremely well and lasts for several years. Do to the nature of an RV bouncing down the road it is good preventative maintenance to ensure that no new cracks or seams pull apart. Dicor stays malleable so it doesn't crack when driving, and has a huge benefit in that it is fairly easy to remove when you need to reseal in a few years. Do not put new sealant on top of old, it rarely works to seal like that and it makes it much harder to remove later. With good Dicor, after a few years you just pull it up real easily and apply the new stuff. If anyone has used stuff like RTV if becomes a huge nightmare to remove, and doesn't last long in direct AZ sunlight. Everyone uses Dicor because it works very well
 
Yes it is nice to have a product that when it fails to seal after 5 or 10 years, that is easy to remove and replace with the same product after replacing all the cheap wood that rotted because of water damage. LOL !!! Probably more damage done walking on the roof replacing the dicor after a while.
 
tonyandkaren said:
Everything made for use on boats is better than what you'll find at RV supply stores. I think people buy Dicor because RV dealers recommend it and it's sold specifically for RVs so they just kind of blindly use it.

Before buying anything for your RV check boat supply outlets, hardware stores, and even Walmart. Prices and quality are often better. If you can't find a part at a regular store try a small RV supply store which will usually be cheaper than Camping World.

How's your roof coming along? I'm hoping that you didn't find any silicon caulk up there - should be outlawed. :-D

Everything made for use on boats is better than what you'll find at RV supply stores. I think people buy Dicor because RV dealers recommend it and it's sold specifically for RVs so they just kind of blindly use it.  In my search for the best RV sealants, "RV sealants" are not the best. I'm looking at 3M 4000 UV right now. Seems (no pun intended) to fit the bill for my current needs. Unfortunately I think you're right about the reason people use Dicor..


How's your roof coming along? I'm hoping that you didn't find any silicon caulk up there - should be outlawed. :-D Silicon city! Mounds of it, lol. Been a real hoot getting that stuff off. Roof is coming along well. Have learned a lot about heat guns, paint remover, Acetone, plastic razor blades and more  :D :-/ . Thanks for asking.
 
bullfrog said:
Most comercially bult RV's are designed to fail it seems as cheaper built means more profit.  RV manufacturers that want to make a profit have to attempt to build a product that will give them the most sales.  A boat or airplane manufacturer couldn't sell a boat that wouldn't float or a plane that wouldn't fly but an RV manufacturer can sell an RV that requires yearly maintenance to keep it from leaking because people who buy them rarely use them and won't pay the price for one built to last.
Yes, yes, and yes.
 
LeaveBehindTheDailyGrind said:
The 3m boat sealants you're referring to are urethane adhesives. They work great, but are almost impossible to remove if you should ever need tip disassemble the parts. Geocell tripolymer roof sealant works well and is available at any hardware storea or home depot.

True. 3M 5300 is permanent. 5200 is half as permanent. 4000 UV apparently is removable. I'll look into Geocell tripolyme. Thanks for the tip.
 
John61CT said:
3M 5200 yes, meant to be permanent, need a chisel to remove.

4200 not so much, stays very flexible, can take it off when needs rebedding, also Sika 291.

Anything's better than sillycone

Yes, my mistake. 5200 and 4200. 3M 3000 UV is looking good to me at this point. I'll look into Sika 291. Thanks.
 
bullfrog said:
Yes it is nice to have a product that when it fails to seal after 5 or 10 years, that is easy to remove and replace with the same product after replacing all the cheap wood that rotted because of water damage.  LOL !!!  Probably more damage done walking on the roof replacing the dicor after a while.

I'll have to agree with your LOL.
 
Jack Grit said:
Everything made for use on boats is better than what you'll find at RV supply stores. I think people buy Dicor because RV dealers recommend it and it's sold specifically for RVs so they just kind of blindly use it.  In my search for the best RV sealants, "RV sealants" are not the best. I'm looking at 3M 4000 UV right now. Seems (no pun intended) to fit the bill for my current needs. Unfortunately I think you're right about the reason people use Dicor..


How's your roof coming along? I'm hoping that you didn't find any silicon caulk up there - should be outlawed. :-D Silicon city! Mounds of it, lol. Been a real hoot getting that stuff off. Roof is coming along well. Have learned a lot about heat guns, paint remover, Acetone, plastic razor blades and more  :D :-/ . Thanks for asking.

Meant 3M 3000 UV not 4000.
 
bullfrog said:
Yes it is nice to have a product that when it fails to seal after 5 or 10 years, that is easy to remove and replace with the same product after replacing all the cheap wood that rotted because of water damage.  LOL !!!  Probably more damage done walking on the roof replacing the dicor after a while.

I suspect that if it's failed you enough to allow wood to rot after 5 or 10 years you should have resealed things sooner... 
If you don't like it you don't like it... I understand different folks, different strokes. But dicor does work and nothing lasts forever.
 
I use Dicor self-leveling sealant as a secondary sealing top layer over the existing cured primary sealant, whether it's butyl, marine sealant, silicone, or whatever.

It works well enough when used this way.

I doubt the self-leveling stuff is supposed to be used as a primary sealant between the mating surfaces.
 
The RV industry could take some pointers from forums like tnttt as far as durability and easy repair. How many improved longer lasting, easier to use products are out there that would produce a better, longer lasting RV? The industry in the United States has continued to design and produce RVs that are not better designed and constructed to meet the needs of most full timers, just inferior, poorly constructed, high maintenance, overpriced profit producing weekend campers. There are a few exceptions but not many mass produced. Take a look at some of the Austrailian manufactures. Starting out using better sealers is just a small part of the problem. This is just my opinion but judging from the number of people building because they cann't buy better there are a lot of people with the same opinion. Take a look at manufacture's recomended maintenance and sealer/roof replacement and how little time they back their products.
 
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