Best hold in thin alumium?

Where in "I have a problem holding thin aluminum, about .080", together for a period of 3 - 4 months in an outdoor environment." did it say it needed to come apart? or how often? He just said it needed to stay together for 3 to 4 months - which his method was not doing. If he gave us an idea of the application we could give him an intelligent solution. He says he only needs 4-5 lbs force but does not tell us what shear strength he needs. He did not say how often it needs to come apart and go together either. Mabee a latch, like a Dzuz is required. Mabee a riveted on piano hinge with a removeable wire would be the proper solution. Mabee it should have a thick bar fastened to the back of the back sheet, threaded for bolts or machine screws. If the holes are near an edge, mabee he should use tinnermans. Mabee he should rivet on nut-plates.

If it only needs to stay together for up to 4 months, once, nothing wrong with pop-rivets - either use backing washers, or just use enough that they hold - do like Zenith Aircraft does - use 50% more than you might possibly need for the calculated forces. (he uses avdels - which are really just "super pop-rivets" and not NEARLY as expensive as Cherries)

Different horses for different courses - and we have NO idea what his application or requirements really are.

(and he DID say he "taped" the screws into the metal - what kind of tape did he use - mabee better tape would do the job - I ASUME he meant he TAPPED them. - but that's not what he said - - - - )

Reply to
clare
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Rivnuts , nutserts or a similar product. John

Reply to
John

Where is Lloyd in this thread? (at least the part quoted here). But I read the "which last a few cycles and then strip out" as implying that it if fairly often removed and reassembled. (Removal/tightening cycles of the screws.) Granted -- he may not have meant that, but then again he may have.

I *think* that those are Rivnuts stood on their heads and photographed from nearly straight above, so it is hard to see for sure, particularly with the rather low resolution in the photo.

O.K. A bit better when I double-click on the original image. It might be Nutserts instead of Rivnuts. I would prefer the Rivnuts if there is enough back clearance for them. And, I would prefer one of the proper tools which B.F. Goodrich made for the purpose.

O.K. .... Here is one on eBay -- but it does not show what the size is: #331046323231

It is likely 8-32 or 10-32 from the appearance. The price looks nice -- especially with the manual.

As for the HF set -- I don't *ever* consider only ten of each size to be useful -- even assuming that you get it right the first time so you don't have to drill one or two out. Personally, I consider a lot of 100 of a given size a better starting point. :-)

The tool shown in the auction above has to be adjusted for both the size of the Rivnut, and the thickness of the sheet metal into which it is being installed. Get it too loose, and the Rivnut will turn (especially if you have the ones without the key), and get it too tight and you strip out the threads. I don't see provisions on the HF tool to make such adjustments, though they may exist.

Here is an auction with better views of a Rivnut (one of many auctions) -- selling in quantities of 25 Rivnuts per package:

#370306923448

If you can get enough of it to prevent corrosion forming, and keep it there, yes.

Enjoy, DoN.

Reply to
DoN. Nichols

I'm surprised you didn't recommend Boogers! They work for ALL those pesky fastening jobs!

Reply to
Tom Gardner

Toggle bolts

Reply to
Tom Gardner

Following along that line of thought... how about Gorilla Snot Adhesive, Epoxy, or even Double Back tape?

Reply to
BottleBob

You know, if we have Godwin's law, and Young's Law. There ought to be a law about boogers. Perhaps we can begin the early drafts of writing such? TG's Law, maybe?

Reply to
Stormin Mormon

snipped-for-privacy@snyder.on.ca fired this volley in news: snipped-for-privacy@4ax.com:

"I have a problem holding thin aluminum, about .080", together for a period of 3 - 4 months in an outdoor environment. I have tried drilling and taping with # 8, 10, 12, fine & course thread machine bolts, WHICH LAST A FEW CYCLES THEN STRIP OUT."

I guess you're so intent on defending your position that you ignored the last part of his statement.

You critcize his spelling, but make your own redactions of his words to fit your meaning?

Lloyd

Reply to
Lloyd E. Sponenburgh

I saved a post and doubled up in this one, OK? ;)

Yeah, they're nuts with shoulders/collars built in. You drill the hole and put the nut through it, then when you pull the trigger, it collapses the shoulder around the hole and secures the nut. Unscrew the tool and you're done.

The old rivnuts we used at Southcom were swaged in from behind. Those had angled shoulders which the nut itself filled in when it was swaged.

I used 3 and have had the set for 20 years since, so I'm fine with the smaller sets. If it was something I used weekly, yes, sets of 100 would be a good thing.

Thread the tool's screw back in and give it another OOMPH! ?

I don't recall having any trouble with any screw or spark plug I put a/s on, ever. I've had one tube of aluminum-based a/s for 35 years now and it's going strong. I don't do much with aluminum, so maybe that makes a difference. It works well on s/s to steel, steel to steel, and steel to aluminum head (spark plugs), though.

Where have you had trouble with a/s?

Reply to
Larry Jaques

************************************* Further information

The aluminum is two 1/1.7" enclosed extrusions which need to be held together till spring, then totally free to move back and forth across each other until the next winter. We live on the Great Lakes and they are storm doors for 70 feet of sliding glass windows walls, kg To reply to this message please remove the AT after the kgs1 in the reply to address. To a conservatist's it truly is a free country, YOU may do whatever they wish. KG

Reply to
KG

Some of that tape is stronger than the base material. They hold war planes together with it. They should make "Booger Tape"!

Reply to
Tom Gardner

The company that makes "Duck Tape" is just down the street. I'll approach them about making "Booger Tape".

Reply to
Tom Gardner

Then you can be wealthy, in addition to intelligent. You're a good example for the rest of us.

Reply to
Stormin Mormon

He says he only needs 4-5 lbs force but does

Yes, this is the kicker. WHY is it coming apart? Differential thermal expansion of the sheets, working the screws until the threads in the rear sheet are destroyed? If so, then either really STRONG clamping force is needed, and the sheets will buckle, or really low force with an ability for the sheets to move when they are heated by the sun.

A LOT more info on the size of the sheets and what is causing the failure is needed to give more than general suggestions to guesses as to what the real problem is.

Jon

Reply to
Jon Elson

Cycles of WHAT? Assembly/disassembly, or thermal cycles? I can easily imagine either interpretation.

Yes, without using an anti-seize coating, I can imagine #8 screws in .080" sheet would be pretty fragile in continuous outdoor exposure.

Jon

Reply to
Jon Elson

Well, tapping #8 holes into extruded aluminum that is outdoors full-time is not going to last. There is corrosion, and daily solar heating that works the panels against what is under them. Some kind of fitting with ability for the panels to slide a bit will help. The mention of Dzus fasteners is a good one, they are used lots on aircraft for this reason (corrosion + thermal cycling) and have stood up well over probably

80 years, now. But, not as easy to install, as you need unrestricted access to the rear part to install the fastener. There are lots of outfits that make specialty fasteners for aluminum things, possibly looking at the Thomas register will give you some leads.

Using liberal amounts of an anti-seize coating on the screws might prolong the life of the threads in the rear part. Also, there may be a screw material that is optimal for use in aluminum, some steel and stainless screws make the corrosion MUCH worse, and the threads will gall massively the first time the screw is removed.

Jon

Reply to
Jon Elson

Even these need to be selected carefully for the right anti-corrosive properties. Either aviation or marine hardware would be a good place to look. Mixing metals in a wet environment will cause pretty bad corrosion in many cases.

Jon

Reply to
Jon Elson

How about an internal expanding rubber plug? Like a boat drain plug but smaller. 1/4" or smaller rubber tubing on a small screw with a washer and nut to draw down and bulge the rubber. Use stainless or bronze for the screws and it shouldn't corrode. Put plug in hole, tighten nut to expand rubber. You could even get fancy and use countersunk heads to ensure expansion.

Reply to
Steve W.

Can you drive a stick of wood into the open end of the extriusion, and use wood screws?? Or put TNuts in the wood and use machine screws?

Lots of "possibilities"

Reply to
clare

I take it this is two door panels sliding past each other? The two extrusions "move back and forth across each other " when the panels move - what's wrong with going through BOTH sides of BOTH extrusions and putting in a pin????

Reply to
clare

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