Attaching Fender Question

[Capebuild]

I'm thinking about getting to installing the fenders. The fenders I purchased have a small return lip that goes up against the cabin body for creating a through hole to screw through and into the cabin body. I'll be putting some fender welting between the fender and the body. But my question is what is a typical screw to fasten the fenders to the cabin body? At first I was thinking of just using a stainless steel phillips head... but then I thought maybe a hex head bolt of some variety might be better.
Any thoughts would be helpful.

Thanks a lot.

John

[MickinOz]

I through bolted the fenders on Ol #1

5 x 1/4" stainless steel bolts on each fender.

The walls are 17mm or about 11/16 plywood, the frame is 3 x 2.
3 bolts through the frame, 2 through the walls.
Big washers under the bolt heads where they contact the camper to spread the load.
Small washers under the nuts on the insides of the fenders.

The fenders are polyurethane.
The idea of the plastic fenders held on with smallish bolts, with big washers at the teardrop end and small washers at the fender end is so that when I hit something I stand a chance of tearing off the plastic fender (replacement cost about $70 per pair) without hurting the rest of the trailer body.
Its pretty common to rake a big furry grasshopper down the side of the car and/or trailer, so I tried to make the fender a sort off tear-off consumable.

If you live where animal strikes are common, you might wanna give some more consideration to screws. Steel fenders aren't going to give much, so you might want to put the "give" in the attachment technique.

Roos can get pretty big.
https://www.youtube.com/watch?v=yH-7CnW_5Yc

[JasenC]

I'd probably go with a #10 SS torx and washer if there's room, the drive slot is going to hold up better then a philips is that location.
I've become anti philips over the years except for things like drywall and lath screws where the bit camming out is to your advantage. I mostly use torx for wood screws, because it's a superior drive system.

[TimC]

I have a similar fender on my TD. I gave some thought to bolting the fender through the wall but decided to use a half dozen 12 x 3/4" SS screws per fender instead. It is plenty sturdy. In the event I run into something I don't want the lower wall destroyed. Rather I would prefer the fender breaks away from the wall. I'm taking a chance with that but I'm more concerned about hitting something while backing up/parking than while cruising the highway. If the fender should get torn off the wall repairs should be minimal. At least for the wall.

[halfdome, Danny]

John, three of the 5 bolts that hold my fenders on are smooth chrome pan head since they attach on the inside.
The mattress hides the 2 lower bolts.
Danny

[Capebuild]

Thanks all for the replies.
When I designed the wall sections (inner, middle and outer layer of ply's) and had them CNC'd, I did leave plenty of wood around where the fenders will be located... so I could use some screw of some sort to fix the fenders in place. The more I think about this and consider the replies.... I was at the hardware store this morning and looked at these stainless screws with a hex head. I like the fact the head is large (the hex) so should hold the fender well. Just need to get a long drive socket to screw them in place.

Thank you all, again.

John

[working on it]

* If I'm not too late to the party, I'd like to suggest adding steel backing plates to your fenders, then leaving a small gap between them and your trailer wall. The backing plate will absorb/deflect/contain damaging road debris (or even a catastrophic blow-out at speed), and the offset from the wall will further protect the trailer. And, as I found out, keep someone that jumped on my fender from tearing it away from the wall (if it had been screwed to it). My rationale, based on some experience with old cars:

fender mounting rationale pictured.jpg (247.83 KiB) Viewed 528 times

* I bought my 16 gauge steel fenders fom Southwest Wheel in Dallas in 2011, for less than in the picture below, but even at the new prices, they have been worth it. I originally planned to wall-mount them, using the backing plates, but since my frame extends 1" outward from the walls, I took advantage of the spacing, and welded them to the frame (with added bracing on the front and rear fender lips. Since someone jumped on one fender and slightly bent in downward (hardly noticeable), I know that his 280 lb weight would've ripped it from the wall, if attached by thru-bolts or screws. zHere's the current listing for the fenders & backing plates (I presume that the backing plates are available separately, too):

fender & backing plate kit, from Southwest Wheel.JPG (83.57 KiB) Viewed 528 times

* Another point in favor of the added spacing: if ever you decide to get a wider axle or wider tires, you might not need to get wider fenders. I installed a wider, stronger axle a year or so after the fenders were on, and the tires still fit under the fender (though the axle was 2" wider). Another year later, I installed much wider LT tires, and made fender flares to cover the 1/4" that protruded from beneath the fenders. These fenders have been worth it ($48 ??? at the time, I think).

[Sparksalot]

Like TimC, I was concerned about sidewall damage if the fender tore loose. I mounted them directly to the frame using purpose made brackets from Tractor Supply.