[smgemelos]

I am getting ready to install a MaxxFan on our Transit Conversion... we are just getting going down the conversion road.

I have been reading a bunch of website regarding the fan installs. And also looking at some of the marine websites.

I likes the Gidget Van approach - using 3M 4200 Adhesive/Sealant to mount the Roof Adaptor to the metal -- but they were not able to use the 3M 4200 to mount the plastic flange of the fan to the Roof Adaptor. So they used Butyl Tape, Screws, and ExternaBond for mount and seal the fan flange.

In my research I found that 3M 4000UV was (according to 3M) same for use on all plastics. Could the 4000UV be used secure and seal the fan to the Roof Adaptor?

It seems I shouldn't need anything else to secure the fan - like screws (the 4000 is a very strong bond)

And it seems I shouldn't need any other sealant - no lap sealant, no externabond tape, etc.

Thoughts?

 

[Budsky]

I put mine (Fantastic) on with the Hein adapter and just a thin layer of regular silicone seal on both sides, not enough to ooze out and it has been fine. It is secured 8 places with SS machine screws and locknuts inside, didn't even use all 16 screw positions.

I did the same method, minus the Hein adapter of course, flat aluminum roof, on my enclosed trailer, 12 years ago and never had a leak....


Personally I would put a few screws in- you already cut a 14x14 hole, whats a few more 3/16 drilled holes.

 

[RandomJoe]

I used only 3M 5200 adhesive to mount mine. Hein's ring to the roof, and fan baseplate to ring. It's been fine so far, including a number of drives down the highway at 70 MPH with it open. (I pretty much haven't closed it since I installed it.)

I did use lap sealant but about halfway through it occurred to me that was probably pretty pointless since the adhesive is a marine grade and should handle rain just fine. It does fill in the screw holes though.

 

[morey]

If I did Gidget's fan again I would probably have just used the 4200 for everything.

From http://moreysintransit.com/install-roof-fan-van/ :

We wanted to avoid using screws and just use 3M 4200 to attach the flange to the adapter. But 3M 4200 contains Xylene which according to the fan instructions shouldn’t be used on the plastic. In hindsight, it probably wouldn’t have mattered and we should of done a small test on the plastic to see what would have happened.

 

[RVing]

Can't imagine why you'd only use glue and not stainless machine screws & locknuts. I've worked w/ 4200 and 5200 in marine applications and while they are great products, would not trust either to keep anything like a fan from blowing off the roof. But if you must, sand first and clean both surfaces w/ acetone... not alcohol as any unevaporated alcohol will prevent the 4/5200 from curing.

 

[smgemelos]

Can't imagine why you'd only use glue and not stainless machine screws & locknuts. I've worked w/ 4200 and 5200 in marine applications and while they are great products, would not trust either to keep anything like a fan from blowing off the roof. But if you must, sand first and clean both surfaces w/ acetone... not alcohol as any unevaporated alcohol will prevent the 4/5200 from curing.

RVing - watching the info from West Marine on 5200 - they use 5200 to mount the lead keel of a boat to the fiberglass hull, or to bond the deck to the hull. If they can use 5200 for that application - it is more than strong enough to deal with some wind.

The only issue with 5200 is that it makes a "permanent" bond -- you'll have alot headache seperating anything bonded with 5200.

4200/4000 are about half as strong as 5200. So, my guess is 4200/4000 are more than strong enough to deal with highway wind speeds.

 

[smgemelos]

Hey Morey

Yeah - that quote you posted on your website regarding the fan install had me pause on using 5200/4200 for the bond between the flange and the Hein adaptor plate.

Then I saw the 3M 4000 product - and they claim is safe for all plastics.

I'll give it a shot.

If I did Gidget's fan again I would probably have just used the 4200 for everything.

From http://moreysintransit.com/install-roof-fan-van/ :

 

[morey]

Important to remember that 90% of the fan is only attached to the flange with 4 small screws into plastic.

Not sure what would fail first, the 4 screws and plastic around them or the 4000/4200/5200.

 

[Hein]

I used 3M Window Weld to bond the adapter to the roof. (Had a cartridge open so needed to use it.) Used Scotch brite pad to de-gloss and alcohol to clean (allowing plenty of time to dry). Butyl tape on the vent flange and lightly tightened flange head screws. Then coated everything with Phil Swift's famous on TV FlexSeal in grey to sort of match the color of the van. I'll brush on another coat of FlexSeal for good measure. The screws along the inside edge went into the sheetmetal and the others are set firmly in the adapter. The fan is offset so the adapter is about 1" thick on the outboard side to allow the vent to sit level. It's seen 3000 miles of highway and rough road travel, multiple rains and car washes.

 

[unclebob]

Keep in mind that when you only use an adhesive & and no screws / bolts you're only attaching it to the PAINT on the roof. If the paint fails for any reason you're SOL.

???

 

[RVing]

All applications are not the same. I've used 4/5200 to bond fiberglass and below waterline fittings w/o issue. My main argument against 4/5200 as a sole fastening system is it will undergo significant thermal stress in an automotive roof application (IIRC there is a rather low operating temp limit with 4/5200, less than 200F anyway) and it is very easy to thru-bolt the fan. Finally, in the fan app, the glue on the leading edge of the fan is doing the majority of the work keeping the fan attached; the load is not distributed uniformly. To each his own.

 

[maricard]

what do you think about Sika Sikaflex 291i Marine bond/sealant to install a fan on my van?
Someone use this product before?

 

[jethaden]

what do you think about Sika Sikaflex 291i Marine bond/sealant to install a fan on my van?
Someone use this product before?

I used 291LOT on fan (plus 3M VHB). See my old thread DIY for details. Works great. Also used on my rub rail and new windlass mounting for my boat. I like LOT (Long Open Time) since it has a longer working window. It is lower adhesion than 5200. Maybe more like 4200 but I do not know much about 4200. A bead of adhesive caulk inside van between frame and roof will like fan frame in place permanently.

 

[Transit Trader]

The 4200 is very permanent! Will make any necessary removal very difficult. Do not use silicone except as a sealant for tubs and countertops, it ruins the surface's ability to have anything stick to it later. Butyl rubber instead. Lived on sailboats 20 plus years, learned about silicone the hard way