Goop / caulk recommendations

My trailer arrived with two soft solar chargers attached to the roof top via a sort of caulk/goop. Two years later the trailer is leaking under the solar panels. Looking for a recommendation for a goop or caulk that is white or clear, and can withstand the sun and heat of the Western USA flying spots?

I use "Goop", whether it is marine, automotive, etc.
Basically it is a silicone (from what I can find online) "RTV", with a thickener. Letting it, or similar, set and then cover (silver/aluminum) tape can extend the life.
Good news, it won't flow all over. It is also cheap from local sources.
Bad news, not much lasts long out in the sun or elements.

Silicone does not take paint well, thus using some sort of tape to cover the seal over time. Latex sealers take paint better, but in my eyes won't last as long even if painted.

On Wednesday, March 14, 2018 at 10:22:11 AM UTC-7, Jonathan St. Cloud wrote:
My trailer arrived with two soft solar chargers attached to the roof top via a sort of caulk/goop. Two years later the trailer is leaking under the solar panels. Looking for a recommendation for a goop or caulk that is white or clear, and can withstand the sun and heat of the Western USA flying spots?

Sikaflex 295 is a UV resistant sealant/adhesive

https://www.merrittsupply.com/produc...e-and-sealant/

3M makes one too, called 4000 UV

https://www.westmarine.com/buy/3m--4...96?recordNum=5

Loctite has their own version cleverly named Marine Sealant

https://www.homedepot.com/p/Loctite-...6891/206156418


If you use a paintable formula like the first two you can also put a UV protective topcoat over the sealant which would extend its exposure limit.

I've had good luck with polyurathane. Silicon only gives you one try since it won't stick to itself.

3M 5200 is a classic boat sealant in white, but takes a long time to cure

Loctite is my favorite. I know they have it in black, not sure about white.

Sikaflex is another good brand

Homedepot has all of the above

the 3m 5200 is what we used on my tail wheel skid it cures in about 12-24 hours if there is enough humidity. In AZ I had to drape wet towels over it. it is very sturdy an a little flexible. Best stuff I have ever used and it is white

On Wednesday, March 14, 2018 at 6:24:17 PM UTC-5, wrote:
the 3m 5200 is what we used on my tail wheel skid it cures in about 12-24 hours if there is enough humidity. In AZ I had to drape wet towels over it. it is very sturdy an a little flexible. Best stuff I have ever used and it is white

3M 5200, available in 7 day cure or 24 hr cure in the boating section of Academy outdoor and Sports
Good luck!!

On Wednesday, March 14, 2018 at 5:52:44 PM UTC-7, Scott Williams wrote:
On Wednesday, March 14, 2018 at 6:24:17 PM UTC-5, wrote:
the 3m 5200 is what we used on my tail wheel skid it cures in about 12-24 hours if there is enough humidity. In AZ I had to drape wet towels over it. it is very sturdy an a little flexible. Best stuff I have ever used and it is white

3M 5200, available in 7 day cure or 24 hr cure in the boating section of Academy outdoor and Sports
Good luck!!

3M 5200 will yellow in the sun and eventually crack where it is exposed, if that is a worry. 3M 4000 will not yellow or crack - at least for a very long time.

On Wednesday, March 14, 2018 at 6:31:27 PM UTC-7, jfitch wrote:
On Wednesday, March 14, 2018 at 5:52:44 PM UTC-7, Scott Williams wrote:
On Wednesday, March 14, 2018 at 6:24:17 PM UTC-5, wrote:
the 3m 5200 is what we used on my tail wheel skid it cures in about 12-24 hours if there is enough humidity. In AZ I had to drape wet towels over it. it is very sturdy an a little flexible. Best stuff I have ever used and it is white

3M 5200, available in 7 day cure or 24 hr cure in the boating section of Academy outdoor and Sports
Good luck!!

3M 5200 will yellow in the sun and eventually crack where it is exposed, if that is a worry. 3M 4000 will not yellow or crack - at least for a very long time.

Jon,

Thanks for the lead on the 3M 4000. I wasn't aware of silane modified polymers & it definitely looks like the better choice for something exposed to UV. Polyurethane (3M 5200) usually isn't a good choice for high UV exposure.

Craig
7Q

I can vouch for the Sika-brand! Just about any gap or joint on wind turbine nacelles or blades gets sealed off with Sikaflex and it lasts for years without fading or cracking. It is a Urethane and it can be painted over. It comes in a variety of colors with white being the most popular.
Uli
‘AS’

On Wednesday, March 14, 2018 at 1:22:11 PM UTC-4, Jonathan St. Cloud wrote:
My trailer arrived with two soft solar chargers attached to the roof top via a sort of caulk/goop. Two years later the trailer is leaking under the solar panels. Looking for a recommendation for a goop or caulk that is white or clear, and can withstand the sun and heat of the Western USA flying spots?

Sikaflex is usually the "gold standard" in the RV industry. Any exterior penetration gets sealed with Sikaflex. Excellent caulk.