What Sealent/Adhesive to use?

[MrWippy]

Hello, I would like to fit a solar panel on my van. Its a flexible 150w panel and I have made a good sturdy frame for it out of aluminium angle bar. I am going to use 3M VHB tape to stick special plastic corner brackets onto the van roof which I think is fiberglass sheet over plywood. I am happy enough with this choice of adhesive as I have looked into it. I was put of with sikaflex and any other super solid PU glue because it sounds way too permanent and messy.

However I could do with some advice on a few things. Firstly what is a good sealant the use? I intend to go around the edges of the plastic feet/brackets to seal them just to keep the tape dry and for tidyness.

The other thing I want to do is use the hole in the roof where the Status antennae was. I want to run the solar panel's cables down through the hole. I intend to keep the fixtures of the antennae. The bits on the outside of the roof of the van where the pole goes through and its seals as is. They are fine.

Then I want to stick SOMEHOW a square click lock lid plastic food storage container over the antenna's hole onto the roof. The storage box is the kind of thing you get in most shops with blue latches on it. It could be made of food grade Nylon. I don't know for sure what its made of. This should keep the rain out and also if any water did seep in there the seals on the antenna's fittings would keep out anymore water. The box need to be firmly stuck on but not super bonded. I also want to run mastic/sealant/ around the joint.

Then I intend to stick a special plastic cable junction box onto the bottom of the food storage box. This junction box is meant for solar panel fitting and has gromets and O rings with it to run the cables into. I want this to be well bonded onto the plastic box. I might use the VHB tape here again. I then want to run sealant round that joint too.

The junction box has a nice groove on its underside to hold sealant/adhesive and a nice flange. It should stick pretty well to the box.

The top of the storage box has a lip all around which I could remove to give me a flat face and flange which might be better and also a good keyed surface as i will file of the plastic lip. The flange should hold a bead of sealant in there quite nicely.

I think I need gap filling ability and UV stablisation.

So what sealant and what adhesive should I use?

 

[tonka]

There you go...

Puraflex 40 PU Sealant & Adhesive

Noticing cracks or expansion in concrete? Purafelex 40 PU sealant will help you fix it quickly. It's a useful tool to have in any construction site or home, as it bonds to most materials. This product will work on concrete, wood, metal, aluminium, polyester, glass, uPVC, stone and ceramic.Thanks...

www.toolstation.com

 

[MrWippy]

Looks good! Good it comes from toostation too. Thanks!

 

[RustyRuss]

Tonka, Sikaflex then...... OP use sikaflex or any other polyurethane adhesive. If you need to remove it at a later date use a Stanley knife blade to make it part company from your fibreglass or plastic body panels. If I read your original post correctly you’re planning to use some kind of sandwich box lid and body as a seal. The sealant you use will be fine for a long time, but your sandwich box will succumb to the effects of uv, sunlight to you and I, the plastic will be brittle and disintegrate inside 18 months and the first time you know it’s failed will be when it’s raining inside your MoHo, go for the proper “designed for the job” fittings, glue them in place with sikaflex or a similar polyurethane adhesive, live comfortably in your rig knowing it won’t leak and that you can cut it all off with a Stanley knife blade if you change your mind. I speak from LOTS of experience of plastic components that have been exposed to sunlight by people trying to DIY protect electrical connections!!

A quick note on the aluminium frame, make sure it is unlikely to suffer from vibrations and develop stress fractures at the bends you will have put in it. Another vote for the plastic brackets and sikaflex solution.

I have re-read my reply to your post and I really don’t want to come across as a ”know all” pain in the ar*e, I just hope I have been able to pass on my knowledge and experience of using all sorts of materials that are likely to be exposed to sunlight, and the problems and issues that are likely to ensue if the wrong stuff is used. Hope I’ve helped!!

Cheers!
Russ

 

[Emmit]

It would seem to be counter intuitive but when you bed both the panel and the box to the roof, make sure you use spacers between the object to be stuck and the roof. Suggest tile spacers 2-3mm
This ensures that the sealant can work (ie stick) between the two and also, should you wish to remove them in the future (and never say never) you can separate the two surfaces with, say a very sharp, thin profile bladed knife.
Been there, done that!

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[steve 6644]

Or, a garrot wire, you can separate lots of things with those and very safe.

 

[MrWippy]

Good point about the UV on the food box....I wonder if I could paint it to give it protection. If it does break down its just a food box. I wonder what else would do the job...hummmm

The other alternative it an actual blanking plate from Status but that looks like it wants to be screwed onto the roof, perhaps I could just use the puraflex to stick it on with.

I just bought some of that puraflex 40. I am using that 3M VHB tape to stick the feet on with so I probably don't need spacers.

 

[RustyRuss]

If you are definitely using the sticky tape make sure you get rid of all the oxidation and muck/dirt that forms on the plastic surfaces before you apply the tape. In fact that goes for anything you stick to the surface of your MoHo, it’s very likely to be ever so slightly dirty, even if you’re a supercleaner! I use those alcohol wipes you get on fleabay to make sure surfaces are pure and clean before I go for it with the glue. Please don’t be afraid to tell me to do one!

Cheers!

Russ

 

[MrWippy]

I have my sanitization rituals carefully planned, a bottle of isopropyl alcohol at the ready!

 

[steve 6644]

Most important, right at the last minute too..

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[RustyRuss]

Nothing like a bit of sanitation..... wear gloves and keep your “face covering” on LOL!!

Cheers!

Russ