Rivet sizes

[Bradrock]

I'm working on the rivets for my spar. My question for people that have done this before - did you trim every rivet to perfect length? For example, in the places where there are 4 capstrips, I believe I need AD5-12.262 rivets, according to the Rivet Sizer app.
So have people used 5-12's (a little short), 5-13's (too long) or have they trimmed every rivet to length? The prospect of trimming every rivet for the capstrips is rather a daunting one!

[marcusofcotton]

Brad, you should be able to stay with the standard lengths mostly. The go/no go gauges are the cheap, quick, and easy way to answer which direction to go, preferably on some scrap test stacks. Too long folds over too easily, but you want to make sure you have the minimum (and little more) .5D height and 1.5D diameter on your shop heads. On some of the shorter -3 & -4s, I found the half sizes very worthwhile.

Mark J

PS - Fortunately, rivets are basically cheap. I have some bags from having calculated the length needed, they didn't work out satisfactorily so I bought the adjacent length as appropriate. Or trimmed, had heard to not buy the cheapest rivet cutter, bought the better one, used it plenty and happily.

[Enewton57]

Hi Brad, I ended up cutting some rivets while making up my spars. A good rivet cutter makes it an easy job. There is a range so in most cases you can get by with a slightly shorter or longer rivet. I tend to move toward the slightly shorter one if I can stay within the acceptable standards. Longer ones have more of a tendency to bent over instead of driving straight.

[Battson]

Brad - if you order from overseas, there might be an option for a half-size that would be close enough? I know you will have a hard time finding half sizes in NZ.

[sjt]

Has anyone found a vendor for half size ad470 rivets?

[marcusofcotton]

I've purchased some from Aircraft Spruce and wicks in the past.

[mswain]

Has anyone found a vendor for half size ad470 rivets?

I don’t recall needing many half size 470 rivets, but I used plenty of the 426 in the smaller sizes when building my wings. B and B always seems to have a good selection of rivets. Vans is where I got my 426 3.5 and 4.5

[rodsmith]

I found a rivet cutter to be a valuable tool. For odd size rivets I just need a few of I cut them down from longer ones.

[svyolo]

Once you get to a 4 or 5 length, the 1/2 sizes go away. I never thought about it, but it is probably because you can start cutting after a 4.

In my very limiited experience, using a rivet a little long results in a poorly squeezed or driven rivet. It falls over to one side.

[bergy]

I've cut a lot of rivets. However one cuts them .... it is important to have a square cut on the end. I think I bought my cutter at OSH and it tends to leave a little burr on the end of the cur rivet. I borrowed a huge pneumatic squeezer from an A&P to use on my cap-strips. It seemed to demand an absolutely square end on the big longer rivets. A quick stroke on a file worked well to assure that the squeezer keeps it straight.

[PaulSA]

The advise from VANS, and my experience in building my RV-10, was that if you are between sizes, go down. Technically, you may not have the full size on the shop head but if the rivet has filled the hole with a half decent head, you probably have 90% of the strength. If you go up a size and clinch it, drill it out, clinch it again........ been there, done that......

Of course, I understand with something as critical as the spar you want to get it right.

[sjt]

I found the rivets I needed from MSWAIN's B&B vendor. I believe PaulSA is correct about using the next rivet size down. The square edge is everything.
I have found rivet cutters to be useless. Correction - I have found rivet cutters to be evil. I have gone to great lengths to avoid them.
My personal method for the AD5 spar rivets seems silly, but it takes less time then removing a single bad spar rivet.

I also recommend Dave Bottita's youtube video on cutting rivets.

https://www.youtube.com/watch?v=ypn5WkxUDQM&ab_channel=DaveBottita