Z-Bracket headache

Hubitom1 · #1 11-21-2010, 08:34 AM

Good Sunday morning, everyone!

Just started to put my tank together, and followed the steps in the Van's handbook (mark the center of each flange, and then drill the holes ... ). I also remembered reading here on the forum that one should offset that line by 1/16th.

I measured the flange to be 17/32nd of an inch wide on the inside.

After measuring the center and moving that line a fraction to the outside (this was supposed to be just a visual test) I held my Stanley rivet puller against that line in order to see where the rivet/hole would end up. To my surprise (disappointment is probably the better word) I saw that the center of the rivet puller would be almost on the outside of the flange. I measured it to be 13/32nd. That leaves 1'8th of an inch from the edge of the flange, which is pretty much unacceptable.

Here's my question. Are there rivet pullers that are narrower? Or do you have to grind of some of the material of the rivet puller in order to get closer to the flange? Are you inserting the rivet crooked in order to get it in somehow (that would probably leave room for leaks, not even talking about structural integrity)???

I'm out of thoughts here. Anyone can guide me in the right direction?

On a side note ... Why can't Van's just make the **** thing 3/4" wide?

Thanks,

Thomas

Brantel · #2 11-21-2010, 08:43 AM

Look in the archives for the "Checkoway" method of doing these. Also, you will need to grid a ton off of most any rivet puller for these and a few other places.

You can remove a bunch of the meat from the nose of the puller, just don't go too far......

Here is a pic from Brad's site:

Here is a link to his site and where he starts his tanks:

http://www.rv7factory.com/log.php#tanks

Dan hates for this method to be referred to as the "Checkoway" method since he got the idea from somebody else but that is what most folks call it.

Hubitom1 · #3 11-21-2010, 09:14 AM

Brian,

just read through Damon Farnsley's web site, and it helped a lot to avoid mis-aligning the brackets, but I didn't see the pic with the ground off gun. The pic you added now really helped knowing that this is the only way.

I still don't understand why Van's is so cheap and not selling Z-Brackets that are slightly wider at the flange. The weight gain is insignificant in my opinion. But that's just my thought. Who am I after all.

Thanks a lot.

Thomas

Kevin Horton · #4 11-21-2010, 09:55 AM

You can also gain a bit of clearance between the rivet puller and the web of the Z bracket by making a small wedge with a hole in it. Bend the nail of the rivet a bit so it is angle away from the web when the rivet is sitting straight in the hole. Put the rivet nail through the hole in the wedge, so one face of the wedge is sitting flat on the rivet. The other face of the wedge provides a flat face for the rivet puller to set against, while the puller is angled away from the Z bracket.

If the visual description isn't clear, you can see a picture of the wedge I made on my site. That page talks about a problem on a different part of the aircraft, but the wedge I used there could help here too.

bruceh · #5 11-21-2010, 03:29 PM

Get yourself a close quarter rivet puller like the one on the left.

Hubitom1 · #6 11-21-2010, 06:37 PM

Thanks to everyone for their reply.

I installed the brackets first on the spar, and then put the tank on top, drilled the outboard and inboard ribs, clecoed them, and then backdrilled through the baffle. Still a headache, but I'll got already a close quarter rivet puller that still needs to be worked on in order to get those rivets in later.

Next tank I'll go the other way around. Drilling the rivet holes first, attaching them to the spar, and then backdrilling the bracket through the spar. The nutplates have more wiggle room!

Again, thanks to everyone.

Thomas

Maxrate · #7 11-21-2010, 07:44 PM

Quote:

Originally Posted by bruceh

Get yourself a close quarter rivet puller like the one on the left.

Bruce,

Where did you get your close quarter rivet puller?

bruceh · #8 11-21-2010, 09:55 PM

My father gave that pop rivet tool to me along with a bunch of other tools when I started this project. It must be at least 30 years old!

It is a USM Corporation PRG412 "Pop" rivet tool.
A google search found that the Pop brand is now owned by Emhart Teknologies.

I've seen these for sale on ebay.

bkthomps · #9 11-22-2010, 07:18 AM

Quote:

Originally Posted by Maxrate

Bruce,

Where did you get your close quarter rivet puller?

interested to know this as well

redwards · #10 11-22-2010, 12:43 PM

As others have mentioned, it is necessary to grind the rivet puller. I bought a cheap harbor freight version for this. Pre-bending the nail is also a good idea. Most importantly, DO NOT follow Van's instructions for the Z brackets. You must find Dan Checkoway's method and follow it. Dan must have gotten bent out of shape about something because he pulled his very useful website, but the Z bracket information is famous and most likely posted somewhere in these forums. In my opinion, the Checkoway method should be adopted by Van's.