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prkaye

Well Known Member
Does anybody know what the difference in weight is between (installed) MK-391-BS rivets and the corresponding solid rivets (AN426AD3-3.5 I guess)?
Weight difference per rivet, or per ten, or per 100?? Not sure how to determine this because uninstalled blind rivets have that stem which adds weight. I guess I could waste a few by pulling htem and then weighting, but it would probably take several to get a meaninful measurement, and at 22 cents a pop, I'm hoping someone already knows the answer.
 
Why not...

Next time you are using blind rivets, why not collect all the spent mandrels, weigh them, and subtract?

mcb
 
Better have a really good scale.

Unless you are weighing hundreds of each kind of rivet, the difference is probably going to be very small and tough to measure accurately.
I'm curious about why you are curious about the difference?
 
I'm curious about why you are curious about the difference?
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You can probably guess... I know I'm going to get flamed for this, but I am considering the use of blind rivets for some or all of my lower wing skin rivets. Vans have confirmed that this is structurally acceptable. On the bottom side of the wing, I'm not concerned about the aesthetics of it, and I'm not really concerned about other builders accusing me of wussing-out. The upside is a potentially big savings in time and headaches. One downside is cost, but in the scheme of things it's not that much. The other downside is weight, so I want to know how much i'm talking about. If it's less than a pound of difference total, then I don't consider this to be enough to worry about.
 
To heavy, to expesive!

When talking to Vans (Ken, or someone), they told me that the reason that we use solid rivets on these planes, is that pulled rivets are a lot more expensive and are a lot heavier to (no mention of how much heavier though!)

Stick with the solid rivets and save both ways!

Regards, Tonny
 
Build it!!

prkaye said:
You can probably guess... I know I'm going to get flamed for this, but I am considering the use of blind rivets for some or all of my lower wing skin rivets. V
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I wouldn't exactly call it a flame but I'm trying to understand the logic??? You've probably spent more time on the computer talking about it and researching the pop rivets than it takes to do it.:eek: I think it took less than an hour to do the last skin on each QB wing panel.

It is not a big deal. Find a friend to help. He, (or she) with the longest arms does the bucking. Done deal. The pop rivets will add some weight, will be faster and definitely more expensive.

Whatever you decide, just do it!!!
 
prkaye said:
You can probably guess... I know I'm going to get flamed for this, but I am considering the use of blind rivets for some or all of my lower wing skin rivets. Vans have confirmed that this is structurally acceptable. On the bottom side of the wing, I'm not concerned about the aesthetics of it, and I'm not really concerned about other builders accusing me of wussing-out. The upside is a potentially big savings in time and headaches. One downside is cost, but in the scheme of things it's not that much. The other downside is weight, so I want to know how much i'm talking about. If it's less than a pound of difference total, then I don't consider this to be enough to worry about.
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You are not alone. I'm considering doing this on my 8A. Not surprisingly I got the same replies you did :)

If you go this route, please share your experience. I for one am interested.

Edit: Here's the thread I started on blind riveting the outboard skin: http://www.vansairforce.com/community/showthread.php?t=23256
 
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For what it's worth , I was able to do my wing bottom skins by myself, 1 per afternoon, 3 hours or so each. You might save some time with pop rivets, but 3 hours isn't that long
 
Phil, I would stay with the solid rivets and spring for the 120.00 for the tungsten bucking bar . Get a helper and go for it, after you get past the first 2 inboard bays it really isn't a big deal . I think you will be glad you went with the solid rivets after it's done.
 
Honest answer...

Just did the 2nd outboard skin on my QB last weekend. It wasn't 1 hr. Maybe I'm slow.

Including prep, riveting, drilling out a few bad rivets, cleanup, and hanging the wing back on the wall (including some moving around of shop equipment), it was 5 hours or so. Oh yeah... I also had installed a Dynon pitot which required riveting of the pitot mount to the skin (probably an hour, just due to finickiness).

It really isn't that big a deal. I maybe would have saved about 2-3 hours per wing (maybe more with a pneumatic rivet puller), which is nothing in the scheme of things, but on top of that it isn't a "hard" 2-3 hours. Of course, you pretty much need a partner to do solid rivets, but again, it is far from the most challenging thing I've done on the build so far.
 
You look like you have long arms?

prkaye said:
You can probably guess... I know I'm going to get flamed for this, but I am considering the use of blind rivets for some or all of my lower wing skin rivets. Vans have confirmed that this is structurally acceptable. On the bottom side of the wing, I'm not concerned about the aesthetics of it, and I'm not really concerned about other builders accusing me of wussing-out. The upside is a potentially big savings in time and headaches. One downside is cost, but in the scheme of things it's not that much. The other downside is weight, so I want to know how much i'm talking about. If it's less than a pound of difference total, then I don't consider this to be enough to worry about.
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You look like you have long arms, you could buck all the rivets yourself if you have had a lot of practice. I did my entire top wing skins last and only needed help with a few rivets. It only took me a few hours for each one.

Use Rivet tape, and if you can get competent help. You will have a much better looking, feeling, and structural job. (aluminum to aluminum) is always better than (steel to aluminum) when it comes to long life for the structure.

Best wishes, Have fun!
 
Weight is not a big issue . . .

prkaye said:
... The other downside is weight, so I want to know how much i'm talking about. If it's less than a pound of difference total, then I don't consider this to be enough to worry about.
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The vast majority of the rivets aren't too hard to do. I did my lower wing skins by myself (all solid). There were a few dozen that I would consider good candidates for pulled rivets. I can assure you the weight difference for just the tough ones would be a a couple of ounces at best for both wings.
 
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