Rivets, Acorn nuts, Rivnuts etc.

[Penny Taylor]

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the outside has a white rounded cap on it about the size of a dime. [/quote]

That sounds like a Snap-Cap, they make them for rivets, as well as nut and bolt installations. Gives it a more finished look. www.pro-dec.com sells them. Penny, TX

[Alf S.]

Hi: I too have started changing the pop rivets to S/S bolts and acorn nuts... I have used nylon washers as a buffer against the fiberglass surface and so far have eliminated most of the water leaks...When removing the old pop rivets I noticed that many of them had indented the Fiberglass and probably aided the leaking by allowing the water to puddle around the rivet heads...Also many of the Mandrels had dropped out of the rivets so you could see blue sky through them...not good The cabinet over the dinette hasn't been done and during a recent downpour leaked like a sieve ... I had to extract the water from between the Ensolite and Fiberglass with a syringe ...3/4 of a cup full!!! I just finished installing a MaxxFan and I used S/S phillips screws supplied with the fan and added S/S weather seal washers @ $0.98 ea. for the 16 screws... and auto body seam sealer(black buytl tape) under the fan support ring!!!Waiting for rain to test my work.
Alf S. North shore of Lake Erie

[Con]

Way to go Alf. You won't regret it!
The one thing I haven't redone is the roof vent, it looks pretty sloppy but hasn't leaked as yet. Another thing for my to-do list. I am still working on my above window cabinet.
Ran out of resin.

[Kurt & Ann K.]

A little more on the "weak link" topic.
We own a 2000 17' Casita. In it's 3rd year, we had 3 aluminum rivets break. These were all upper cabinet support rivets. Above the kitchen vent, we keep coffee cups, coffee and an old stove top toaster. That accounted for one rivet. That same cupboard on the street side accounted for the other two. The contents there are toilet tissue and a few books. The rivet holes had not enlarged or become oval. I used DAP ALEX PLUS 35 yr. caulk on the rivet shaft and then head before installing the cap. No leaks yet in 4 years. No stress cracks in the fiberglass and no more rivet breakage either.
I'm a believer in the "if it ain't broken, don't fix it" school of thought. I've also had fix-it projects backfire when the fix proved too strong for the job and more expensive damage was the result. Figuring out that kind of thing, is why engineers make the big bucks. Parts cost analysis is not their only job. Repair cost analysis must also be figured into the equation.
Please ponder the whole picture when considering "improving" the original design.
That said, there have been improvements in caulking and adhesives since many of our "eggs" were hatched. Even there however, one should use caution so that a new caulking material or adhesive doesn't work too well and make repair a virtual impossibility.

Thanks for providing a topic revealing the different viewpoints. We all learn from such a discussion.

Kurt & Ann K.

[Benny K]

I`ve been experimenting with the SS machine screws....most have been on the trailer for 4 years and there is no difference in the stress cracks that were there from the POP rivets till now.....on some of the screws I used flat rubber tap washers as a seal under the screw head, and on others I punched washers out of bicycle tire tube.....neither leaks.....On the inside I used SS flat washers and SS hex nuts to initial tighten and then followed with SS acorn nuts as jam nuts and haven`t had any loosen off.....I don`t travel on back roads and stay away from washboard so the trailer is not really straining the screws.....I better not speak too soon, as I haven`t started preparing the 13' for camping yet and think that our first trip will be a long one.....( little too warm here in the cold white north...temp was 32 degrees).... may find a problem but don`t think so, at least hope not,LOL.....Benny

[Joe Z]

Benny....
I think i like the idea of the bicycle tube as a gasket between the stainless steel screw.....and the tap washers...... the tap washers i take it are the flat washers you put inside a faucet to stop the dripping?
The rubber in between while it is great for leaks would also be good for a vibration dampener..........
And the backside SS washer,hex nut, acorn setup is good too.....................

Kurt and ann k......i also like the alex caulk idea too which would be alot easier
But Four years and no problems from both idea's is a pretty good test. thanks for the feedback.
Joe

[Pete Dumbleton]

The "weak link" theory is not the real reason rivets are used -- They are used because they keep the cost of manufacture down. If SS hardware and rubber gaskets were used, with the need to adjust the threaded bolt tension and the need to find solutions for the blind applications, both the materials and labor costs would go up. Not sure how the washer and the cap base mate...

I was a proponent of "replace the rivets with rivets" school, but having read of some experience from some of the Scampers group on SS, I would try a few SS bolts.

I have had an original rivet pull through the fiberglass roof in one place (but it doesn't leak because the dab of silicone outside isn't flawed.

BTW, the good solution for an overhead cabinet breaking rivets is not to replace the rivets with stronger fasteners but to drill more holes and install more fasteners to spread the load across more of them and on the fiberglass (and to check the existing rivets to see if any are loose, letting the cabinet "work".

[Martin D]

Pete is correct in the reasons rivits are used has nothing to do with a weak link necessity. Having been involved in the marine industry in previoues years and familiar with fiberglas boat and yacht manfacturing I know rivits are used in the lower cost units to save labor and the expense of threaded stainless fastners. Fiberglas boats are subjected to much more stress than the average fiberglas egg and the better and high quality boats use stainless/threaded fasteners for their greater strength and durability especially where two surface are joined together such as the hull deck joint. A stainless bolt and retainer properly installed on a fiberglas trailer is almost always a better long-term soloution than an aluminum rivit. The rivits will suffice for most of us - it does not mean they are a superior fastner. Martin

[Doug Mager]

Thus far in my partial redo of our inside(s) I have chosen to go S/S bolts with ni-lox nuts, maybe less chance of them backing off due to viberation(?)

[Con]

Right on Martin. That is basically what I have been trying to get across for some time now.

[Joe Z]

I think you have convinced me and am going to give the stainless steel threaded a chance.... you put up a good argument.
Joe

[Yellow Boler]

Hi. Old thread. But, I was wondering how the ss bolts have held up over time. I am considering this as an alternative to rivets for the cabinets.

[gordon2]

Originally Posted by Yellow Boler

Hi. Old thread. ...

Only nine years! LOL

More recent threads:
http://www.fiberglassrv.com/forums/f...air-66869.html
http://www.fiberglassrv.com/forums/f...ets-52218.html
http://www.fiberglassrv.com/forums/f...ers-73885.html
http://www.fiberglassrv.com/forums/f...ews-56647.html
http://www.fiberglassrv.com/forums/f...uts-61802.html

For what it's worth, I found that my Scamp, new in Sept. 2015, already had two bolts instead of rivets - straight from the factory. It seems that Scamp thinks they are OK, and in high stress locations, even necessary even though they are more trouble and more money.

A few caveats however. It would be easy to over tighten and damage the fiberglass. There are no torque values available to guide you. Also, the Acorn nuts appear to be a bad choice with bolts. Ny-lock nuts work better. After one of my acorn nuts on a bolt came loose, I ended up using a Ny-lock nut and the acorn nut on top of that since the bolt was long enough. Lastly, use marine quality stainless steel.

[k corbin]

..or you could just get an acorn nut that has a nylon insert (nylock)

[gordon2]

Originally Posted by k corbin

..or you could just get an acorn nut that has a nylon insert (nylock)

Makes you wonder why Scamp used the standard acorn nut on the bolts in my trailer, one if which worked loose.

[Jon in AZ]

Probably because that's what they keep on hand. There's no reason to use pricier nylocks in their usual application as decorative covers for the rivet ends.

The real question is why Scamp used two bolts instead of rivets in your build. I'd guess something wasn't fitting quite right and rivets weren't holding. Instead of finding and fixing the fit problem, they just got a bigger hammer, so to speak.

[gordon2]

Originally Posted by Jon in AZ

..

The real question is why Scamp used two bolts instead of rivets in your build. I'd guess something wasn't fitting quite right and rivets weren't holding. Instead of finding and fixing the fit problem, they just got a bigger hammer, so to speak.

Well... it is in the roof of the larger fridge / microwave cabinet, so there is a lot of weight involved. So a stronger fastener kinda makes sense. The acorn nut on one side loosened only because the bolt was too long for it to snug down, but once I put the nylock nut on, things stayed solid on that side of the camper.

On the other side however, the bathroom wall separated from the shell a little when a rivet failed.

[Jon in AZ]

I do wonder whether Scamp does the same on all builds with that configuration. I haven't heard anyone else mention it, but it's the sort of thing that probably wouldn't get noticed unless there were an issue.

[gordon2]

Originally Posted by Jon in AZ

I do wonder whether Scamp does the same on all builds with that configuration. I haven't heard anyone else mention it, but it's the sort of thing that probably wouldn't get noticed unless there were an issue.

See http://www.fiberglassrv.com/forums/f...tml#post602736

[Borden]

I am replacing all rivets with same size closed end aluminum rivets. The new rivets head changes shape on install; head cups hiding the 1/32 thick neoprene washer under head and they say are water tight to 500 psi. Doing rivets as each cupboard has the original paneling replaced and any repair that maybe needed.