Broken Bigfoot vent, round one above bathroom - Fiberglass RV


Reply
 
Thread Tools Search this Thread Display Modes
 
Old 03-16-2016, 11:31 PM   #1
Senior Member
 
Name: John
Trailer: '84 Bigfoot b17
British Columbia
Posts: 116
Broken Bigfoot vent, round one above bathroom

Hi, it been awhile, but back rolling with a fibreglass rv! We sold the trillium 4500 in the fall, and were sad about it, but now scored a pretty nice Bigfoot and fairly local to us too. It is quite a bit roomier than the 4500 and the gals are very happy about having a bathroom. 2 kids, 2 adults btw.

When checking over the unit to buy, I noticed one vent was broken and needs replacement as it currently is gobbed with silicone. Has like 16 screws in it. The unit is an 84 and here is a picture. Where can I buy a replacement vent? And what is this vent for anyways?
Attached Thumbnails
image.jpg  
__________________

__________________
Tyhee is offline   Reply With Quote
Old 03-17-2016, 12:36 AM   #2
Senior Member
 
Carol H's Avatar
 
Name: Carol
Trailer: 22' Airstream Formerly 16' Scamp
British Columbia
Posts: 11,731
Registry
Looks like the bathroom vent - is it not? Pull down on the handle on the inside to close it?

Perhaps the make is a Ventline??? You need to read what it says on the top to see the make/brand.
__________________

Carol H is offline   Reply With Quote
Old 03-17-2016, 03:08 AM   #3
Senior Member
 
Borrego Dave's Avatar
 
Name: Dave
Trailer: Casita SD17 2006
California
Posts: 2,919
Carol's right, it's a air vent. The "pull up" it says on the top only means that's how the top comes off to replace the cap as long as the base is still good. No clue to why there are so many screws though. If it's a cap for the holding tanks any vented cap would work fine. The vent pipe 1 1/4/ 1 1/2" will be about an inch above the roof and sealed for water penetration. The cap is only there to keep water from entering the pipe. I replaced mine after the UV ate it up. Had to fill the original holes as the new one only had 6, easy peasy. When my desert sun eats this one up I've got a metal one on hand .
__________________
Borrego Dave is offline   Reply With Quote
Old 03-17-2016, 06:08 AM   #4
Senior Member
 
Name: Jack L
Trailer: Bigfoot B-17 CB
Washington
Posts: 1,226
I had to replace one a few years ago. Camping world sells them for a few dollars. Butyl tape is a must for this project too. The roof is curved and the vent is molded to fit a flat surface. The vent material is somewhat flexible so to get it to conform to the roof curve, it needs lots of screws. These are air vents for the grey and black holding tanks.
__________________
Jack L is online now   Reply With Quote
Old 03-17-2016, 08:24 AM   #5
Senior Member
 
ZachO's Avatar
 
Name: Zach
Trailer: 91 Bigfoot 17
Montana
Posts: 944
Registry
Here is where I got mine. Not sure of what exactly the other places (like Camping World) sell, but as you can see from these, there are a lot fewer screw holes.

I replaced both of mine on my Bigfoot because it just seemed like it was time. My advice is to use multiple layers of butyl tape, and do it on a hot day so the plastic is nice and soft and willing to bend, and take it slow so you don't force it to bend too quickly and break.

I used 3 layers of butyl tape and once some was squeezing out and compressed I called it "good enough" even though the vent was still nowhere near touching the roof yet. To me it looks like the plumbing you'll find underneath this vent when you remove it is actually sealed really well. The vent cover is really just to keep stuff from going down into the the plumbing. So it doesn't need to be sealed as well as the larger vents on your roof, though it can't hurt to make sure it's sealed well anyways...
__________________
ZachO is online now   Reply With Quote
Old 03-17-2016, 10:25 AM   #6
Senior Member
 
Carol H's Avatar
 
Name: Carol
Trailer: 22' Airstream Formerly 16' Scamp
British Columbia
Posts: 11,731
Registry
Quote:
Originally Posted by Borrego Dave View Post
Carol's right, it's a air vent. The "pull up" it says on the top only means that's how the top comes off to replace the cap as long as the base is still good. No clue to why there are so many screws though. If it's a cap for the holding tanks any vented cap would work fine. .
Your being generous Dave. I realized after I posted that it probable was not the bathroom vent/fan but the holding tank stack as you suggest.

I am currently looking at replacing the one on my new to me trailer as well and wonder if anyone has used the 360 Siphon type of vent? Just would not do the install it the way they have in the video! LOL apparently the installer is not big on cleaning up old caulking and using butyl tape. The RV Doctor seems to like this type over the traditional type that the OP has.
Carol H is offline   Reply With Quote
Old 03-17-2016, 10:40 AM   #7
Senior Member
 
ZachO's Avatar
 
Name: Zach
Trailer: 91 Bigfoot 17
Montana
Posts: 944
Registry
Yeah these two smaller vents are the vents he's talking about

Click image for larger version

Name:	image3.jpg
Views:	7
Size:	169.2 KB
ID:	93469

Mine didn't have the usual Dicor all over them, and I wondered why, until I removed the old ones and saw that they aren't really meant to "seal". They just cover the "holding tank stack" as you're calling it (which I'll use cause I can't think of anything better to call it!), which itself seems to be pretty well sealed, at least on my trailer.

I didn't take photos of the new ones I installed yet, but I did use Dicor, just in case. And since they were sitting so high off the roof, with my 3 layers of butyl tape, you can imagine how much Dicor I had to put on there...kind of a mess. But that's ok.

I wasn't willing to try to screw them down as tight as Bigfoot did. I really thought the plastic was going to break. So I just did like I mentioned before: slowly tightened each screw more and more, until there was butyl tape getting squeezed out a bit all around, and called it "good".
__________________
ZachO is online now   Reply With Quote
Old 03-17-2016, 02:14 PM   #8
Senior Member
 
Name: John
Trailer: '84 Bigfoot b17
British Columbia
Posts: 116
That really helps! Thanks a lot everyone. I don't have an rv place in town or even really close to us so I have to be as best prepared as I can before we head to the city to buy supplies like this. Thanks for the links to vendors, I hope my "local" rv place will stock these as common item, and the install tips are great. You guys and gals rock!

I wonder if a light torch "adjustment" would be useful to help create a bend tomatch the roof line profile? Maybe I'll get a spare or two

What do you recommend for filling unused holes with?
__________________
Tyhee is offline   Reply With Quote
Old 03-17-2016, 02:25 PM   #9
Senior Member
 
ZachO's Avatar
 
Name: Zach
Trailer: 91 Bigfoot 17
Montana
Posts: 944
Registry
I can definitely get behind supporting your local shop, but there comes a point when it's just easier to order this stuff off the internet.

Not sure I'd use a torch, but if you're willing to experiment and possibly "sacrifice" one of them, I'd definitely be interested to hear how it works! I think just a nice hot day would be plenty. It was in the 50s when I did mine. I think a nice sunny day in the 80s would have been perfect.

The butyl tape will fill in any unused holes.
__________________
ZachO is online now   Reply With Quote
Old 03-17-2016, 02:43 PM   #10
Senior Member
 
Carol H's Avatar
 
Name: Carol
Trailer: 22' Airstream Formerly 16' Scamp
British Columbia
Posts: 11,731
Registry
Quote:
Originally Posted by Tyhee View Post

I wonder if a light torch "adjustment" would be useful to help create a bend tomatch the roof line profile? Maybe I'll get a spare or two

What do you recommend for filling unused holes with?
Having cracked a new roof bathroom vent recently during install having over done the butyl tape under it (but was using rivets rather than screws) I highly recommend not going overly heavy on the butyl tape. Its probable not really necessary anyways. Especially if you are going to put any kind of additional sealer around the vent lip after.

An Epoxy putty stick will do the job for filling small screw holes not needed. J-B Weild has a few products. I have used the Waterweld Epoxy Putty to fill a couple of screw holes on the roof with success.
Carol H is offline   Reply With Quote
Old 03-17-2016, 11:38 PM   #11
Senior Member
 
Name: John
Trailer: '84 Bigfoot b17
British Columbia
Posts: 116
Really liking the tip on the JB weld epoxy putty! Thanks Carol. I'll let you all know what I come up with for a replacement vent and any custom heat massaging!
__________________
Tyhee is offline   Reply With Quote
Old 03-18-2016, 01:32 AM   #12
Senior Member
 
Carol H's Avatar
 
Name: Carol
Trailer: 22' Airstream Formerly 16' Scamp
British Columbia
Posts: 11,731
Registry
The key to the epoxy putty is to make sure you clean up around the hole your filling before it drys otherwise you will be sanding and creating a bigger mess.
Carol H is offline   Reply With Quote
Old 03-18-2016, 03:03 AM   #13
Senior Member
 
Borrego Dave's Avatar
 
Name: Dave
Trailer: Casita SD17 2006
California
Posts: 2,919
Quote:
Originally Posted by Carol H View Post
I am currently looking at replacing the one on my new to me trailer as well and wonder if anyone has used the 360 Siphon type of vent? Just would not do the install it the way they have in the video! LOL apparently the installer is not big on cleaning up old caulking and using butyl tape. The RV Doctor seems to like this type over the traditional type that the OP has.

I've never seen this one before Carol. Guess if you go with it you can let everyone know how it works out. I agree, the installer missed the prep part but he sure liked the top sealant .
__________________
Borrego Dave is offline   Reply With Quote
Old 03-21-2016, 01:54 PM   #14
Member
 
Name: Josh & Sonya
Trailer: '97 Casita SD 17; 03 Bigfoot 25RQ
Arizona
Posts: 80
Hot air gun

Quote:
Originally Posted by Carol H View Post
Having cracked a new roof bathroom vent recently during install having over done the butyl tape under it (but was using rivets rather than screws) I highly recommend not going overly heavy on the butyl tape. Its probable not really necessary anyways. Especially if you are going to put any kind of additional sealer around the vent lip after.

An Epoxy putty stick will do the job for filling small screw holes not needed. J-B Weild has a few products. I have used the Waterweld Epoxy Putty to fill a couple of screw holes on the roof with success.
Hi John and Carol,

I've used hot air guns (about $15 at most hardware stores) for doing all kinds of shaping of PVC as well as warming up reinforced hoses to slip onto hose barbs. Old aquaculture trick...The hot air guns usually have two temp settings, kind of like a hair dryer.

Depending on the plastic, this might work to shape the vent base to conform with the curved top; much more controllable than something like a propane torch. Heat the base a little, put in place and see if you can get it to bend to the right shape. If not, heat again until you get it right.

Have a squirt bottle or just a container with cold water handy. If the heating and "molding" process works, keep the vent cover in position and squirt it with water so that it cools down in position with the right shape.

Depending on the plastic (and even with PVC), you can still overdo it and burn the plastic. Best to take it slow until you get the feel of how hot it needs to get before it is pliable.

Good idea to have a spare on hand in case the heating technique bombs out. I like the idea of butyl tape a well.

Good Luck with the repair, with all the good advice in this series, I'm sure it will come out well.

Josh
__________________

__________________
Josh and Sonya W is offline   Reply With Quote
Reply

Tags
bigfoot


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Wheels on the trailer go round and round Jay Marlette General Chat 4 07-06-2013 12:24 PM
Bigfoot: Enlarging bathroom vent from 10" to 14" pindraak Problem Solving | Owners Helping Owners 11 06-02-2012 12:07 PM
Bathroom or no bathroom, that is the question.. Warren Shumway Care and Feeding of Molded Fiberglass Trailers 71 04-07-2012 05:28 PM

» Upcoming Events
No events scheduled in
the next 465 days.
» Virginia Campgrounds

Reviews provided by


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 09:31 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.