Frustrated with Nutplates

I hesitated to post this but now after my fifth attempt to get this right I must

Did anyone else have trouble with the rivets on the Fuel Tank Attach Nutplates on the Main spar? Problem: I end up with the rivet proud of the surface despite the countersink being good.

I have tried:

- Flush riveting - not pushing the bucking bar into the shop end and thought I was putting lots of pressure on the factory end.

- Back riveting - difficult to get the back rivet plate in place, would be curious how others set this up if they did it this way. I already put those five rivets in so clamping the plate is not an easy option.

These rivets are too far inboard to use a pneumatic squeezer.

Section of the plans I am talking about:



Any help would be appreciated. I am going to move on because I am beyond frustrated with these. Of course the next step is to start deburring the ribs but at least I can get into the zen of that

Thanks,
Jeff

Nutplates

Jeff,

Nutplates can be frustrating. From your description you have tried several techniques. One you did not mention that works well for me is to hold the nutplate securely in place with the appropriate size screw. I have one screw of each size that I keep for this purpose.

Keep trying, It will get easier
Marvin

M McGraw said:

Jeff,

Nutplates can be frustrating. From your description you have tried several techniques. One you did not mention that works well for me is to hold the nutplate securely in place with the appropriate size screw. I have one screw of each size that I keep for this purpose.

Keep trying, It will get easier
Marvin

Click to expand...

Marvin,

Thanks. It is actually not the nutplate that is moving around, but instead the rivet itself which ends up with the flush end proud of the surface because obviously I am either releasing pressure on the gun, or actually not sure what else... One spar I was able to complete this with several attempts using flush riveting but this other one is fighting with me.

Have you tried using a C-frame?

I have the Avery C-frame and used it several times for items like this. I put the squeezer set in the base of the C-frame and placed the C-frame on the floor. Then lay/block up your spar on the floor so that the spar is flush and square to the C-frame and using the the avery driver shaft set into the C-frame and rivet gun to set the rivets. Make sure you are pushing down on the spar and that the rivet is flush/square before you set the rivet.
This helps to hold the work steady, gives you the leverage to hold the rivet flush and takes care of any alignment issues with the rivet gun or bucking bar.

Hope it helps.

crabandy said:

Have you tried using a C-frame?

I have the Avery C-frame and used it several times for items like this. I put the squeezer set in the base of the C-frame and placed the C-frame on the floor. Then lay/block up your spar on the floor so that the spar is flush and square to the C-frame and using the the avery driver shaft set into the C-frame and rivet gun to set the rivets. Make sure you are pushing down on the spar and that the rivet is flush/square before you set the rivet.
This helps to hold the work steady, gives you the leverage to hold the rivet flush and takes care of any alignment issues with the rivet gun or bucking bar.

Hope it helps.

Click to expand...

Andy,
You saved the day. I was so focused on more conventional methods that I forgot about this. Just did one and it worked perfectly. Thanks!

Tape

Are you using tape on your flush set? Some folks put tape on their flush set so it doesn't scratch their skins or move around too much during riveting, but I've seen it result in flush rivets not being so flush...

Compren is right. Try a rivet with one layer of scotch tape versus a rivet with 2 layers of masking tape. Big diff. The masking tape one will be domed and may even have a tape texture print on the head.

Great, glad it worked for you!

I honestly don't remember any particular issue on either spar. I'm pretty sure I used a single piece of scotch tape and back riveted them.

propsync said:

I honestly don't remember any particular issue on either spar. I'm pretty sure I used a single piece of scotch tape and back riveted them.

Click to expand...

I think in my case I had trouble setting up the back rivet plate so that it sit flat and flush.

Answering the other questions/comments: I didn't have any tape on the flush set, but am using one of those flush sets that has the red plastic sleeve around it (used on Wing skins, etc). Another builder I know called me and suggested in the future to get a flush set that has no plastic protection around it for these situations and I will do that.

In the case of the c-frame the set up was just perfect so I moved past this frustration in literally five minutes.

Thanks again to everyone. It's funny how some steps are easier for some and harder for others..