I have never like rivets at all and had great fun drilling them all (almost all) out of my Scamp. Zip-pink, zip-pink. I had a bucket full of the little devils. I hoped I could find a better way--better looking, better stronger, not rustable...better. I ran across these "Thermoplastic Rivets" in the hardware store. They are just like the regular ones, but hard plastic and larger. The smallest size is 3/4". In one store, a bag of 100 cost $21. Another store, same bag $14. Anyone have experience with these little puppies? Thanks

These? Did you intend to put in a link? Any comment anyone makes is likely to be inaccurate without seeing the particular rivets.

Andrew

Plastic rivets with time become brittle & break. The best rivet replcement is ss bolts.

Don Meyer(Mech Engr)

Sorry, I've been away for awhile. The product is called Sequentia Structoglas FRP Drive Rivets. It's a rivet. It looks like a rivet. It is made of high impact thermoplastic. They are used to attach FG panels and wall fixtures. They are used to attach sheathing to metal, etc. I thought might be good for attaching floor to frame. Cabinets to FG., etc. I'll learn to link...I promise.

Nylon Drive Rivets

These are installed by hammering the pin IN.

They must look rather ugly on the inside. I like ss bolts and acorn nuts.

My curiosity got the better of me...a little google excursion found these.

Thermoplastic Rivets

Could be quite interesting for Fiberglass Trailer applications in areas where the stress levels were not too great.

I will leave it to some of the engineering members to compare the pull and shear numbers to the aluminum rivets.

On looking over the information on the web a little closer, I see the Canadian Distributor is only about 4 or 5 Miles from my house. I'll try and drop by next week and see if I can get some samples for testing

Thanks, Charlie. I thought they might be worth a look. Another supplier is http://www.Nudo.com/rivets They have photos, etc. I am always interested in new or different ways to tackle old problems. Contrary to some folks, I usually have the attitude that ANY change is bound to be an improvement. Gets me into alot of trouble.

Any items made of plastic, and I don't care what kind it is of the 4,000 main families and 24,000 derivatives, when exposed to Ultra Violet light from the sun, will eventually detoriate and then become brittle and then desintegrate.
Enough said?
Go stainless steel when ever possible.

Kristi, et al,
When the fiberglass TT body becomes stressed during an emergency manuever or a rough road or even a good sized pot-hole where is the "weak link"? With aluminum pop-rivets, the fiberglass generally proves stronger and the repair only requires replacing the rivet. Using a bolt will require a much more involved repair of the fiberglass, particularly if the cracks are deeper than surface stress cracks. Stress tests of plastic rivets used with fiberglass will need to be published to convince me to change. The issue of UV deterioration might be addressed by including an ingredient in the plastic formula which would counteract the problem (possibly lamp-black). Painting or caulking the head of the rivet could also be the answer and may even be a requirement to prevent moisture from seeping in along the stem.
In my youth, I always attempted to make things stronger, assuming stronger was better. As I've added a few years I've discovered that axiom isn't necessarily true. Among many other examples, automobiles are designed with "crush zones". Not for the purpose of making the manufacturers rich by boosting the number of parts required for repair, but to protect the occupants so they don't have to be repaired. It became smarter for the car to be the "weak-link" than the human being riding inside.

Please consider all the ramifications of your decisions before starting in a direction which may not allow you to go back to the starting point. Come to think of it, that advice is appropriate for nearly all aspects of one's life.

Kurt & Ann K.

Why?

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Ever!!!!!

Seems that these thermoplastic rivets are for a very light duty application judging from their blurb....I wouldn`t be the one trying to hang up the overhead cabinets with them unless the trailer was going to be a static display and the cabinets empty.....also not the prettiest looking pieces when compressed......I`ll stick with my SS machine screws and SS acorn nuts for interior trim... ..I had small stress cracks under my aluminum rivets in my 13' Boler and in the 4 years since I switched to machine screws, the stress cracks haven`t noticeably changed .......and they could have been originally caused by loose stretched aluminum Pop rivets wiggling around in the holes while trailering.......Benny

I'm going to agree with Kurt on this issue. The only SS bolts on my trailer are the ones I just added to hold the Horizon Case Awning. The problem was needing to cut the insulation and the rat fur to get to the shell so I could put the nylon lock acorn nut on (plus I added 1-1/2" fender washers.) For this particular application, I think the bolts/nuts was the best answer, but for nearly everything else, I'd prefer to use rivets, also for the reason Kurt mentioned. I'd rather replace a rivet now and then, than fix fiberglass.

Ok. SO I've taken the belly band off the boler. Scraped the layers of paint off and burnished and buffed and pollished the metal back to new[almost]. So what do you suggest for fasteners when I reatach after the new paint goes on in the spring? The rivits held for 20 plus years, laid fairly flat, and were barely noticeable. I guess a no 4 or 6 stainless flathead screw would work if I redrill the holes and countersink them. How much am I going to gain?

Thannks, Gina. I remember you from when I initially joined. Another woman in her "Element". I have always enjoyed YOUR sense of humor! Monkeys! no less.

Click to view attachment

There are rivets.... and then there are rivets. These ones are intended for installing fiberglass linings inside washrooms, etc, and have two problems that I can see:

- The rivet grips by expanding in a deep hole and gripping the sides of the hole. In 90+% of applications on a trailer, you have a shallow hole (ie, it is in thin material) so this rivet won't grip.

- I am uncertain about the pull-out strength of this sort of rivet, even if it is fixed into thick material. I can see it's shear strength is good but its pull-out strength only needs to be enough to stop a sheet of fiberglass dropping off a vertical wall - not the same as holding overhead cabinets in place over bumps!

Andrew

All of these comments certainly give food for thought. Much to consider. Thank you.

I have always disliked rivets, as well.

My first problem with them was that they are single-use: you have to drill them out to remove them, then install a new one to reassemble. That's not a big deal in many trailer applications, but is a real pain when they are used in small appliances, etc.

The next problem is that they are usually quite soft (to make them easy to install), and so they stretch and distort under load. Since they can't be tightened, there's that replacement again.

The latest frustration which I have had with them is that in soft materials (such as fiberglass), they need a washer or other part on the inside to pull against, or they do not expand and grip well. That takes much of the "blind installation" advantage away, so it's an annoying single-use fastener without a balancing advantage.

I understand the idea of deliberate weak links. My lawn mower uses a couple of plain rivets as shear pins connecting the blade to the motor shaft, so if I hit a hard object they shear and I only need to replace them (for a few cents) rather than having engine or major blade damage. What I don't understand is how cabinets fastened into a trailer should need a weak link. Does the interior of your car fall apart on rough roads?

None of this means that rivets should not be used. In factory assembly, the few seconds or few cents saved by each rivet (verus a nut and bolt) adds up to be significant, where it is irrelevant in my repair or modification work. In a factory environment, exactly the right size and type of rivet can be used for best performance, and pneumatic pulling tools ensure fast and repeatable installation. Also, while they stretch and fail, they don't loosen in the way a nut can back off of a bolt, so they are in some sense more reliable.

I think that all of this would apply to the thermoplastic rivets as it does to the aluminum and steel rivets which I have dealt with so far.

I'm only guessing, but I suspect the thermoplastic rivets would be inadequate for any cabinetry, but might be fine for small items such as service (water, power) entrance fittings.

I think there's a big difference between an automobile and a fiberglass trailer. Automobiles are made of steel. Steel fastners whether bolts or rivets still the weak point. Automobiles are designed to with stand lots of impact energy and are quite ridgid. Automobile bodies don't flex and bend while driving down the road, there's an internal steel structure to keep everything from flexing and moving around.

Fiberglass trailers are made of fiberglass which is a plastic. There is no internal steel structure to force them to hold their shape so they will flex and move as they bounce over bumps and etc. The cabinets provide some support the reduce the amount of flexing, but stop it. As things flex and move something will have to give eventually, your choice whether it's the rivets or the fiberglass.

Yes, of course, I agree; however, they are not completely dissimilar. Even a car is not completely rigid, as anyone can see who has jacked up a corner to change a tire and found that the doors are not fitting very well. The difference is that the car body is rigid enough to keep the flex within the limits of the components, without resorting to weak links, short of an actual collision. When the body flexes, the plastic trim, dashboard, windows, and whatever else is not forced to move so far that their fasteners shear off. Modern cars are much more rigid that those of a few decades ago, as structural design has improved; I think our trailers are firmly stuck in the 1970's, but even the cars of the 70's didn't pop their interiors apart (well, 1980's Dodge interiors fall apart, but I don't think it's the same effect... )

A closer comparison might be an Airstream trailer. Like a typical "egg", this is a body shell carried by a basic steel frame. The shell holds itself up, but would not handle the load of being used without the support of the frame; I have no idea if the interior fittings are expected to help. Do Airstreams shear rivets when driven? Seriously, I don't have one and don't know - any thoughts from the Airstreamers among us?

In any case, I agree that if the fastener through the shell might apply huge forces that could damage the fiberglass (such as for a cabinet, not just an electrical cord entrance fitting, for instance), shearing a rivet would be better than cracking fiberglass.

Hi James, for the belly band I`d go with aluminum rivets since all they do is hold the belly band in place and will last indefinitely.....what will wear somewhat is the hole in the fiberglass......I`d replace the old rivets with new in the existing holes and then run an extra rivet in a new hole in between where the old rivets were....worked for me! .. ....Benny

Hi: I don't have a problem with Rivets... It's "Rosie The Riveter" that bothers me!!! Alf S. North shore of Lake Erie

I am also an Airstreamer, and I've never lost a rivet yet, not even on my 1953 ! Airstream rivets are blind rivets, but I don't see that would make any difference.

IMHO using ss rivets defeats the purpose of rivets in respect to fiberglas applications! Aluminum has the give that is required and if they break, they have done their job of NOT CRACKING the FIBERGLAS and showing there is a stress problem or in the case of the AlCan Hiway, was a problem. DITTO for using steel screws!
Just MHO
chuck h.

I believe the primary reason the various manfs over the years have used rivets is ease of production, plus they are hard to under- or over-tighten -- I believe the rivet as "fuse" theory that many of us have espoused is really more icing on the cake.

Some folks have used SS screws and nuts without problems and some folks (myself included) have had the original aluminum rivets pull thru the fiberglass anyway, so experience has varied -- BTW, some of the Yahoo Scampers have been involved in aircraft building and have said that the rivets Scamp uses are of excellent quality.

Buddy, on Yahoo Scampers, got his reriveting techniques down pat and has completely reriveted both his Scamp 13 and his Scamp 5W, working alone with an inside Acorn-nut holding tool he devised.

Maybe you could get Buddy to post pics or diagrams of his Acorn Holding One Man Tool. Or does he want to sell it, where's the line???? I AM SERIOUS!!!
chuck h.

A small rolled up round piece of butal caulk, stuffed into the acorn nut, will hold it on the rivet end. It will also provide some extra sealing for the rivet core if the outside seal leaks. Several can be set at a time, after the intial space take up has occured.
zig

Basically, what Buddy (and Joy, separately) came up with is a short piece of aluminum pipe, plus two pieces of PVC pipe, all sized to fit inside each other -- One end of the alum pipe is crimped so it loosely fits an acorn nut but the nut won't slip inside it -- Other end of alum pipe is fastened into one end of PVC pipe -- That pipe, in turn, slides into second PVC pipe -- Loose rivet (plus cap base and sealant) are slid in from outside -- PVC pipes are adjusted inside, with SS hose clamp around smaller diameter piece, so the pipes fit from floor to ceiling or side to side with a curve in them to keep things tight -- Acorn nut is put in end of pipe and the rig is set on the rivet with the other end tight on floor or wall -- Then go back outside and do the rivet with the rivet tool.

To work on his 5W, he built a portable outside stand, like aircraft techs use to work on aircraft (He's USAF retired).

I'm sure you're right there, Pete. I will add a couple of outsider's thoughts on rivets breaking:

If, let's say, 10 rivets aren't strong enough to keep a joint together, it would be logical to put, say, 20 rivets in - after all, it's the fastener or its substrate that's breaking, not the whole moulding. Halve the load on each rivet and both it and its surrounding fiberglass are less likely to break. Of course that's also twice the potential leak paths.

The best way of joining fiberglass mouldings is by bonding, but that is permanent and expensive in a production setting. What works on exactly this problem in yachts is to 'bond' in the minor mouldings using a polyurethane sealant/adhesive (examples are 3M 5200 and Sikaflex 221). This doesn't need to be all round, just along some strategic joints, and the rivets would then be largely superfluous, though useful to hold the moulding while the sealant sets. Removal is difficult, but not impossible - a hacksaw blade worked along the gap will part the mouldings.

Andrew

I'm a newbie who's still looking for his first egg (a Scamp 19' "Standard" 5th wheel, if you happen to be selling), but I do know something about blind "pop" rivets that some of you may have overlooked.

Blind rivets are used in lots of construction projects. I'm familiar with "Avex" blind rivets, which are specialty items used in airplane/airframe construction. Avex rivets are specifically designed for joining thin aluminum layers together in settings where high-reliability is an absolute must, but there are many, many different variations on the blind rivet theme.

Blind rivets all work more or less the same way: a tubular sleeve with a "T" head has a nail-like thing passing through it. You insert the sleeve through holes just big enough for the sleeve in the two (or more) things you want to rivet together and add a hard steel washer to the back side, then pull the nail-like (called a mandrel) thing through the sleeve. The nail deforms the sleeve up to the point where it runs into the steel washer, then the nail breaks off, leaving an enlarged "tail" jammed tight against the steel washer and all the layers btween it and the rivet's "T" head. It's a quick way to join two things together using a fastener that won't unscrew or otherwise work loose over time.

The most common blind rivet is the "Pop" rivet (a brand name). You can buy them in hardware stores: they're cheap and good for lots of things, but they are not very strong and (as many people have remarked) they can leak water up the mandrel sleeve.

Enter closed-end rivets. Closed-end rivets are built almost the same way "Pop" brand rivets are, but instead of having a channel that's open at both ends for the mandrel to pass through, closed-end rivets have a solid cap enclosing the inside end so it can't leak. Prep the inside edge of the "T" at the top of the sleeve with a dab of sealant applied with a paint brush (to keep the layer thin so it doesn't interfere with the mechanical holding action of the rivet) and that joint will stay watertight longer than the fiberglass underneath. Just remember to get rivets with aluminum or stainless steel mandrels, which won't rust and leave rust streaks down the side of your egg.

You can buy them here: http://www.hansonrivet.com/w22.htm and other industrial fabrication suppliers.

--Peter

Hi: Thanks my one daunting task for next season is to remove the windows 1x1 re seal and re rivet them back in...trying to make them water tight and rust/streak free... this info. may be just the ticket!!! Alf S. North shore of Lake Erie

Hi: again...just remembered some one once told me that an aircraft was described as a "million rivets flying in close formation" Is that True??? Alf S. North shore of Lake Erie

This dexcription has been in use in the RAF (British Air Force) for a very long time. Generally the pilot is Pontius, Henry is the navigator and maintenance is done by Mortis, the rigger.

Andrew

And it all depends on Cptn. Murphy!!! Alf S. North shore of Lake Erie

Not actually. Closer to half a million. http://www.boeing.com/commercial/757family/pf/pf_facts.html

In general, however, there several times as many rivets in a small, all-metal airplane than there are other metal parts. The materials list for building the rudder on my Zenith Zodiac 601XL lists 14 metal parts and 320 Avex blind rivets.

--Peter

... and that's just the rudder!

Peter, I see you have a fiberglass egg, not an Airstream. Tired of rivets?

That Boeing site does not have a similar count for the latest 787 Dreamliner. Too bad - that one will be almost half composite, and even in all-aluminum models I'll guess that for the same size of aircraft, more recent designs have fewer rivets, and depend more on adhesive bonds.

I think Andrew has a good point: aluminum blind rivets in soft material are not really suitable for major point loads, and loads on sheet material shouldn't be concentrated either - rivets in sheets should be sharing the load in large groups, like stitches in a sewn seam in fabric. No I'm not about to start drilling dozens of holes in my Boler...

Bad idea! I also removed all my rivets & replaced them w/ss no. 10 bolts w/lock nuts.
Plastic rivets can fail under stress from the trailer walls moving around while out & about.

Don(Mech Engr)

Hi Don,
I have a few questions. If I replace old style rivets with Stainless Steel bolts.
#1 What size and length would I use?
#2 Would'nt I have visible bolts on the inside of my Trillium 4500?
#3 How would I tighten them up in Blind Spots on the interior of my trailer?

Thanks,
Dave In Michigan

I know its nice to redo everything at the same time, but I do have to ponder this: If the rivet isn't broken, and if I don't need to remove it to fix something else, is there any reason to take all my rivets out and replace them?
(Thanks to Donna who reminds us to use the search engine. Now I can add to this topic instead of starting my own about rivets!)

My opinion..No... "if it ain't broke, don't fix it." For me, the only exception would be to pull non-leaking windows and reseal with NEW butyl...if I was going to paint.

my 2 1/2 cents.

Ditto here.....wait till they start leaking.....Benny

The beauty of aluminum pop-style rivets is you set them and they stay. They don't unscrew themselves and don't generally slip or fatigue, which is why something very like s pop-rivet is used extensively in homebuilt aircraft kits. When they do start to leak, it's generally the fault of the sealant around the rivet or (more likely) the sleeve where the mandrel "head" inside the rivet shakes loose, creating a nifty little channel water can leak in through. This can happen just about any time in the rivet's long life. So, unless you go to a (more expensive) closed shaft rivet like the one I mentioned earlier on in this thread, you're not buying yourself anything by replacing them, and may be causing trouble by tearing out a known water-tight seal and replacing it with a new seal that won't be any more dependable and might well be worse.

--Peter

Ok, I took a look at my Major Project trailer. Some rivets have been replaced. Some nuts, some acorn caps, some have held on by rust. I will be doing some replacing for sure. Thanks for all the advice.