[Daida]

Hi erveryone.....

this is my issue:

As my shop can be heated it still is a mayor act, and over longtime a cost issue as well, i?m i little bit concerned about the rivet temperature while driving them.
As aluminum expands and shrinks when exposed to warm/cold temps so do the rivets itself.
If i put the rivets in with the ambient temperature during wintertime (German Winter, pretty much around freezing point and below!) they will expand in warmer temperatures and the bond of the riveted parts will be less strong than before, right?????
So now i thought about before heating the entire shop i could come up with a rivet heater, so i can actually drive preheated (warm, not hot or even glowing) rivets that will actually tighten the bond when cooling of.....

Has anyone thought about that already or even constructed a rivet heater???

Or ist temperatur not that much of an issue while driving rivets????

Or is the rivet heating up itself enough during driving due to cold-deforming?

thanxs in advance.....

daida

 

[videobobk]

A couple of things here. Rivets, if they were heated, would cool in seconds! By the time one was inserted into the hole, the bucking bar placed, and everything check prior to driving, it wouldn't be over a few degrees above the temperature of the structure. If it were hotter than the structure, it would shrink then as it cooled--not a good thing. Rivets will go through thousands of heating/cooling cycles every year. Everything pretty much does the same thing--together. If anything, near freezing is probably close to the middle of the temperature range they will see.

The real benefit of heating the shop is to the builder, not the aircraft. Warm hands just work better...

Bob Kelly

 

[Dean Pichon]

I used to heat the bucking bars

A portion of the build of my -4 was done in an unheated garage in winter in New England. I used to preheat the bucking bars in order to be able to hold them. I agree with the previous post that there is no realistic way to heat rivets (or keep them warm). You may be able to heat skins, though. Either way, I never have noticed any difference between rivets driven in the cold and those driven in the heat of summer. I haven't run the numbers, but guess the temperature swing is too small to worry about

Keep your hands warm!

 

[Guy Prevost]

Your rivets get quite hot in the few moments it takes to set them. There is a lot happening in that part of a second. They cool down just as quickly. I don't believe any ambient temperature you could stand could possibly make a difference in the quality of your rivet job.

 

[C-GRVT]

I would be inclined to think that you are over analyzing a non-issue. If cold aluminum rivets are installed in a cold aluminum structure, then as things heat up, firstly, you are not talking about much temperature difference, and secondly both rivet and structure will expand together.
If anything, installing rivets cold might result in a tighter fit - but nothing that could possibly be realistically measured or matter.
Some years ago there was some talk and even an RVAtor article about heating wing skins during riveting to reduce oil canning. I doubt that there was any consensue or evidence that it actually did anything other than add another complication to the rivetting process.
Bill Brooks
Ottawa Canada
RV-6A finishing kit