To Seal Fenders to Wall ... or not?

Anything to do with mechanical, construction etc

To Seal Fenders to Wall ... or not?

Postby Tim C. » Tue Jul 10, 2018 10:50 pm

I am almost ready to mount aluminum fenders to my sandwich foam/ply walls. I have locations noted where I have solid wood, to receive threaded inserts.
I am contemplating attaching the fenders such that there is a small gap between the fender and wall, through the use of 1/8 inch thick plastic washer. This should allow drainage and no water accumulated.
Has anyone tried this technique and have feedback on its success?
My experience with creating ease of drainage between wood parts on my cedar deck that I designed and built 25 years ago, and the success of this approach, has steered me to seriously contemplate this option.

Any other ideas or are people just laying down lots of caulking?
Tim C.
Teardrop Inspector
 
Posts: 12
Joined: Tue Nov 07, 2017 6:52 pm

Re: To Seal Fenders to Wall ... or not?

Postby halfdome, Danny » Tue Jul 10, 2018 11:14 pm

Personally I wouldn't leave a gap as it will allow freeway driven rain to attack your door seals.

I always use fender welt between the fender and exterior wall but that's just for a vintage look.
My first two teardrops I used the "T" nut application and it worked fine but I forgot them on TD #3 and found out that was just fine.
This way I just drill the holes through the finished walls without having to hunt and peck where the "T" nuts are located.
I put 5 bolts on each fender, three of them you can see on the interior so I use chrome plated ones even though the mattress covers all of them but the top center one.

I've never had a water penetration issue doing it this way since I use a liberal amount of sealant in the holes and on the threads and pan head 3/8" bolts.
I also seal the under side of the fender to wall connection and spray rubber undercarriage sealant (Walmart sells it in a spray can) on the underside of the fender and the wall.
This way everything is sealed and looks black for the black tires.
:D Danny
ImageImage
"Conditions are never just right. People who delay action until all factors are favorable do nothing". William Feather
Don't accept "It's Good Enough" build to the best of your abilities.
Image
Teardroppers Of Oregon & WashingtonImage
User avatar
halfdome, Danny
*Happy Camper
 
Posts: 5413
Images: 161
Joined: Sun Aug 14, 2005 11:02 pm
Location: Washington , Pew-al-up

Re: To Seal Fenders to Wall ... or not?

Postby working on it » Wed Jul 11, 2018 9:22 am

Tim C. wrote:I am almost ready to mount aluminum fenders to my sandwich foam/ply walls. I have locations noted where I have solid wood, to receive threaded inserts.
I am contemplating attaching the fenders such that there is a small gap between the fender and wall, through the use of 1/8 inch thick plastic washer. This should allow drainage and no water accumulated....
  • I have no experience with attaching fenders directly to either foam or wood trailer walls, but many years of experience with using steel fenders attached to trailer frames, using inner shields of steel, or hard plastic, on mostly open trailers. I've seen, and experienced damaged fenders, from encountering large road debris... or in one case where a tire blew-out, and the shredded tire had enough force to damage my thick steel fender (I was driving at 75+ mph), but my race car on the trailer was untouched, saved by the inner fender shield.
  • If you need to attach your teardrop or TTT fender directly to the wall itself, and not isolated from it, by frame pr suspension mounts, then use heavy-duty hardware, and use an inner shield (backing plate) in any case. Using 1/8" spacers might allows water to drain from the fender-wall interface, but if a backing plate is used, it will make the spacer unneeded. On my squareback trailer, I used both a frame-mount, a backing plate, and also left a 1" between cabin wall and fender assembly; no water or dirt ever touches the wall, protected by the isolated fender (I can easily clean my wall behind the fender, also, with a thin sponge).
  • My trailer is an odd width, 50", and my floor is 48" wide (my walls sit on top of the floor, giving me 46.5" inside cabin width), so that left me with the 1" gap between frame edge and walls, making attachment directly to the sidewalls infeasible. And, with my first axle not having brake backing plates, the free-floating fender assembly that I would've used (I've admired them on many street-rods, and wanted to build one) was impossible also. So, frame-mounting was the best choice, in my case. Since my design intent was for a heavy-duty, semi-offroad trailer, I bought heavy steel fenders with optional backing plates, welded the plates on, and welded (not by me, but by a pro,,,I didn't weld when he was available!), and welded them onto the frame in five spots (not a continuous weld, to avoid warpage), with stiffening bars (1" steel angle) on front and rear fender edges (also welded to the frame). Very strong, very protective!
  • fender mounting rationale pictured.jpg
    fender mounting rationale pictured.jpg (247.83 KiB) Viewed 180 times
    alternative fender-mounting ideas; I recommend using an inner shield on all fenders
2013 HHRv a "squareback/squaredrop" 4x8 TTT,
semi-offroad?, at barely under 2000 lbs travel weight
  • 3500 lb Dexter EZ-Lube axle, w/brakes
  • 27x8.5-14LT all-terrain tires (x 3)
  • LED lighting, triple fans. Pioneer stereo
  • A/C & heat, Optima AGM, inverter & charger(s)
  • extended-run, on-board, 2500w generator
  • Coleman dual-fuel stove & lantern, Ikea grill
  • zinc/stainless steel front racks
153929148599153928155112
User avatar
working on it
1000 Club
1000 Club
 
Posts: 1690
Images: 440
Joined: Tue Oct 04, 2011 9:05 pm
Location: DFW Texas
Top

Re: To Seal Fenders to Wall ... or not?

Postby Swan » Thu Jul 12, 2018 1:20 pm

I would never seal the fender to the wall . I have bolted mine on with plastic bolts in four spots. I use plastic as I want the fender to break away if the tire was to blow out. They are strong enough to hold the fender on without vibration but they are no means a seat or a step. A fender bolted though a wall can get major damage from the repeated slapping of a half mounted tread .
Camping in 6X12 Express Cargo Trailer
User avatar
Swan
Teardrop Inspector
 
Posts: 16
Joined: Sat Jun 16, 2018 3:45 am
Location: On Top Of A Mountain Looking Down On The World
Top

Re: To Seal Fenders to Wall ... or not?

Postby halfdome, Danny » Thu Jul 12, 2018 2:26 pm

We had a blow out at 70 mph last summer.
Image
No damage to the teardrop or fender.
The black on the fender edge is where the tire rubbed the under coating off.
:D Danny
ImageImage
"Conditions are never just right. People who delay action until all factors are favorable do nothing". William Feather
Don't accept "It's Good Enough" build to the best of your abilities.
Image
Teardroppers Of Oregon & WashingtonImage
User avatar
halfdome, Danny
*Happy Camper
 
Posts: 5413
Images: 161
Joined: Sun Aug 14, 2005 11:02 pm
Location: Washington , Pew-al-up
Top

Re: To Seal Fenders to Wall ... or not?

Postby noseoil » Fri Jul 13, 2018 10:16 am

Since the fenders were attached to the frame already & matched the tires pretty well, I left the gap in place. I did add a bit of diamond plate (attached to the aluminum skin with stainless screws & sealed) to the inside of the opening against the trailer. Didn't want any rocks bouncing off of the .040" aluminum skin & it works well enough.

153777
Build log: viewtopic.php?f=50&t=60248
The time you spend planning is more important than the time you spend building.........

137905
User avatar
noseoil
1000 Club
1000 Club
 
Posts: 1327
Images: 95
Joined: Sun Apr 27, 2014 8:46 am
Location: Tucson
Top

Re: To Seal Fenders to Wall ... or not?

Postby halfdome, Danny » Fri Jul 13, 2018 1:12 pm

Swan wrote:I would never seal the fender to the wall . I have bolted mine on with plastic bolts in four spots. I use plastic as I want the fender to break away if the tire was to blow out. They are strong enough to hold the fender on without vibration but they are no means a seat or a step. A fender bolted though a wall can get major damage from the repeated slapping of a half mounted tread .


What if the fender completely broke away and hit a car or motorcycle behind you? :frightened:
There's a possibility it could hit a windshield or someone on a motorcycle.
:D Danny
ImageImage
"Conditions are never just right. People who delay action until all factors are favorable do nothing". William Feather
Don't accept "It's Good Enough" build to the best of your abilities.
Image
Teardroppers Of Oregon & WashingtonImage
User avatar
halfdome, Danny
*Happy Camper
 
Posts: 5413
Images: 161
Joined: Sun Aug 14, 2005 11:02 pm
Location: Washington , Pew-al-up
Top


Return to Teardrop Construction Tips & Techniques

Who is online

Users browsing this forum: No registered users and 3 guests