Sealants: butyl tape, dicor, sikaflex, etc. - plugging holes

[Madoxen]

What a great thread...

Yes agreed and could save someone from a sticky situation ?

 

[MTVR]

Yes agreed and could save someone from a sticky situation ?

This thread should be stickied...

 

[IdaSHO]

On doors, windows, etc, that are designed to mount but not be adhered, I stick to gaskets...

MD branded self adhesive EPDM works incredibly well, just stick it to the backside of the door, window, etc you are installing.

Just be sure to orient the cut ends on the bottom.

 

[86scotty]

For roof vents I generally use butyl, stainless hardware and then cover that with a silicone or caulk. I've done many this way on fiberglass roofs and not had a problem. I think my method could be improved with Sikaflex instead of box store caulk/silicone over the hardware and around perimeter but I've never tried it.

I think Idasho is spot on using gaskets for windows/doors.

@Abitibi, isn't Eternabond tape really expensive these days? I've always loved the idea of it but not the price.

EDIT: Just Googled it. I was wrong, it's really not expensive at all compared to other quality methods/sealants. About $1/foot. Left my question intact for the benefit of others.

 

[IdaSHO]

Speaking of roofs...

Substrates and camper construction will vary, but I will always advocate for a liquid applied silicone roof coating if adhesion isnt an issue.
This is a place where there really is no such thing as overkill. Redundant sealing against roof moisture/leaks is key.

I use GacoRoof. Its a single part silicone that you can touch up, re-coat, etc.
Many silicones once cured has trouble bonding even to itself, not Gaco

As an example.... take this "solar tube" dome I used on ours for a sky-light.
Our camper exterior surface is marine ply, epoxy coated and painted with a single stage alkyd enamel.

Bedded in a layer of clear silicone caulk, pre-drilled and fastened with stainless wood screws, then overcoated with a few coats of GacoRoof.

After the first coat.... it goes on thick

Similar method applied to wire glands on the roof for solar cables.
No silicone used for adhesive, the roof coating already installed acts as a gasket when the gland is fastened down.
Then over-coat with more Gaco.

Same goes for roof attached tabs like solar panel brackets.
Fastened down with stainless wood screws to existing silicone roof coating, then overcoated with Gaco

 

[Ducstrom]

On doors, windows, etc, that are designed to mount but not be adhered, I stick to gaskets...

MD branded self adhesive EPDM works incredibly well, just stick it to the backside of the door, window, etc you are installing.

Just be sure to orient the cut ends on the bottom.

Great idea in the gaskets!

Couple questions; on a door or window that is screwed on rather than clamped would the screw go through the gasket or beside it? I'd think the seal could be compromised driving a screw through it.

Also, do you achieve even pressure screwing down the flange with the gasket behind? I feel it'd be tough to not end up with a 'wave' to the flange if clamped too hard where the screws are.

I checked some of the product data sheets and it looks like I'll be going with butyl tape under flanges (possibly a door gasket), and either 3M 4000UV or Teroson MS939 (most likely the Teroson since it's available in grey).
Turns out the 5200 and 4200 are not UV stable unless coated and neither are recommended for metal to wood/fiberglass sealing.

Thanks again everyone!

 

[IdaSHO]

Great idea in the gaskets!

Couple questions; on a door or window that is screwed on rather than clamped would the screw go through the gasket or beside it? I'd think the seal could be compromised driving a screw through it.

Also, do you achieve even pressure screwing down the flange with the gasket behind? I feel it'd be tough to not end up with a 'wave' to the flange if clamped too hard where the screws are.

I checked some of the product data sheets and it looks like I'll be going with butyl tape under flanges (possibly a door gasket), and either 3M 4000UV or Teroson MS939 (most likely the Teroson since it's available in grey).
Turns out the 5200 and 4200 are not UV stable unless coated and neither are recommended for metal to wood/fiberglass sealing.

Thanks again everyone!

The EPDM is softer and compresses easier than any buytl, so no, no problems with wavy flanges anywhere.

I use it for surface mount (fastened thru) as well as trim ring mount. Both work great with this method.

If you do go butyl, make sure you are using the proper stuff. There is more than one type.
I've seen lots of instances where the "wrong" type is used, and it simply doesn't last.

EPDM in this application will seal and last essentially forever, without having the issues associated with adhesives.