MaxxFan Upgrade Questions

lapowers57

I have a Maxxfan 7500 sitting in the garage.  I will pull the paperwork out tonight and start planning this upgrade. Before I start pulling the old fan out of my T@B Max S and find any gotchas in this project, I thought I would reach out and ask for any suggestions, tips, etc from those who have done this upgrade.  I am especially concerned with removing the old caulking without doing damage to the trailer and that the wiring from the old fan is in the right location to feed the new fan.  I did a search and read all the articles that were here but no one had a step by step report on how they did this.

ChanW

It's pretty straightforward, and easy. Removing the old caulk mainly takes patience, and long arms. Also, besides the edge having been caulked with silicone goop, you'll find that the flange has been sealed with the stays-soft butyl tape caulk/sealant. Clean that off with mineral spirits, as well. Re-apply/replace the butyl tape somewhat warm, so it will compress and fill the voids.

I tightened the perimeter screws very gradually, going around the frame a number of times, tightening a bit more each time, so the butyl would have a chance to compress and squeeze out. I actually did this tightening over a week-long period, with the Tab sitting in the sun, but that might be a little excessive B-). Then you can cut off the excess butyl, and clean the surface for the final edge caulk.

The wiring is no problem. I remember putting a notch in the final trim piece to be sure it had an easy 'channel' to use, but I don't think it was absolutely necessary to do so.

I also re-used the final trim piece from the fantastic fan, because it was already the right depth for the Tab ceiling thickness. The color is a bit different, but not really noticeable. (At least my DW didn't notice!  )

Rather than using silicone as the final edge-caulk, I used marine-type caulk, 3M 'Fast Cure 5200' adhesive sealant. It's got a great reputation for keeping boats leakproof. Your Tab will probably float better!

lapowers57

Thanks.  Since I need to do this outside I will need to watch the weather and may need to wait till next spring when I can expect a good stretch of warm weather.

3M 5200 is pretty much a permanent bond.  Great stuff until you need to remove it.  I may stick to silicone for that.

ChanW

Yeah, I figured my install was somewhat permanent (or at least I wanted the seal to be permanent!), so 3M 5200 made sense.

That's one thing i appreciated about the MaxxFan - it has a 'two step' installation. The basic 'frame' installs, and then the 'guts' of the thing are  simply screwed onto the frame with 4 screws. Makes it a simple job to replace, if need be, with another MaxxFan anyway.

Good luck!

FuzzyYanni

I just did this. The main serious gotcha is lack of roof support. If you put any weight on the roof it will dent (st least on a 2010 DM it felt like this)
I bought two foamy pads for gardening and a platform style ladder. Never stepped on the roof and didn't even push my elbows on it without the pads underneath.

The old fan was held in place with Dicor. After watching 3-4 YouTube videos on the subject I decided to use for flat Dicor roll, and the self-leveling caulking tube (more runny)

Permanent sounds like a really bad idea.

ChanW

Well the 3M 5200 isn't much more 'permanent' than silicone, it seems. (See http://www.boatingmag.com/marine-solvents-for-removing-5200#page-7 ). Silicone has always been tough for me to remove, except mechanically cutting and scraping.

Why wouldn't you want a 'permanent' seal on your roof fan?

FuzzyYanni

Silicone is the absolute worst thing on trailers. Also, there is no such thing as permanent anything on the roof of a trailer, it all needs replacement after a few years and the UV rays breaking down either plastics or other components. I just removed 7 year old dicor for my fan project and it was still somewhat malleable like playdough. That means its still working and doing its job. It's also removable with a lot of effort. So if anything claims 'permanent' I would question this, plus knowing that one day I will be removing it to really caulking, I really don't want to get the belt sander out....

ChanW

I agree about silicone. Hate the stuff. Isn't that what your previous fan was caulked with? It seems to be what they used 'most all over our Tab.

I was glad to be removing the silicone from a fairly flat surface when I removed the original Fantastic Fan. It was easier to use a blade on it that way.

FuzzyYanni

Nope, it was Dicor. If yours had silicone the previous repair person was clueless.

FuzzyYanni

Look what came in the mail today ! Another MaxAir 7500K for our T@DA !