Newer Than Newbie Rivet/Dimple Questions.

Hiya Folks,

My tools finally arrived today so I spent the entire afternoon/evening in the "hangar" trying to build my practise tool box. I just ordered another one from Vans (I'd rather this than mess up my actual airplane)

What I found was a couple of things. I'm pretty sure I'm doing things wrong. I have a DRDT2 dimpler. Once I set up the dimpler, as per the instructions, and I dimpled the end pieces and the body I noticed that it actually bent the metal. So instead of a nice straight piece, I had a bowed piece. When I assembled the pieces the box ended up not being straight, to the point where the lid wouldn't sit properly. Did I over dimple my holes? How do you set up the DRDT2 dimpler for dimpling? The rivets ended up being flush so I'm not sure why it bent the metal.

I tried using my pneumatic squeezer to set some rivers, and to dimple, but I couldn't figure that out. How do you set the squeezer up so that you can set rivets with it? I found that the 2 ends wouldn't meet up to squash the rivet. Do you have to add washers to make the gap smaller? Same with dimpling, I found that the dimple dies wouldn'y merry up flush with one another, so it actually looked like no dimples were done. Can you adjust the 3 inch yoke so that you get good dimples and rivets?

Riveting - I used my 3X rivet gun, but I found it was hard to control. The manual says to set the PSI at 90, which is what I did, but the head bounced all over the place. I looked on You Tube and saw that some people set the PSI down to 30-40 PSI. Is this the norm? What are the secrets to riveting? How do you know you have made a good shop head? What does a good shop head suppose to look like?

Bucking Bar - I have a tungsten bucking bar. At one point I laid the bar on my work bench, put the piece of aluminum on top, and then hit it with the rivet gun. I think it squashed the shop head too much (due to the unforgiveness of the work bench as opposed to just holding it in your hand), as the rivet just popped right out (shop head popped right out of the rivet hole). What is the correct way to use the bucking bar?

All in all the tool box ended up being a dog's breakfast and I binned it. Fortunately, the tool box will not be flying me from point A to Point B so I don't mind screwing it up. This was my first time in metal shop in 28 years, or so. So much to learn again! Any tips/suggestions/help you guys and gals can provide, IRT dimpling, riveting or anything else, would be greatly appreciated.

My day started off great, as I waited for these tools for 2 weeks, but it ended in frustration Hope this isn't a sign of things to come!

Cheers

Chris

No worries!

Chris,

Don't get too discouraged. I bet everyone on this list has a bent metal story.

Your dimpler and squeezer work in a similar fashion. The end of the simpler that moves up/down is designed to screw in and out to adjust the distance that the piston travels. This allows for different dimple dies and different thicknesses of metal. Your squeezers will work the same way. As for the bucking bar and gun, this takes practice. I would suggest using the bent tool box as a practice piece. Drill some holes, try some dimpling at various adjustments, and use your bucking bar and gun in separate hands. The tungsten bar may be too small to use laying flat on the Bench. If your tool set came with a back riveting plate, try to use it if you want to rivet flat on a table.

Call me if you need some help.

Keith
770-265-6447

I strongly urge you to take the EAA sheet metal class. Made all the difference for me. Jack D. taught it (Canadian repeat offender IIRC) and it was superb.

One other ? as well......

........ if the plans call for a 3/32 rivet, for example, what dimple dies are you using? The 3/32 dimple dies or something bigger/smaller? My gut tells me that it is probably the 3/32 but stranger things have happened

Cheers

Chris

DRDT2 answer

As for the DRDT2, you are actually under dimpling, not over dimpling. I had the same problem. Lower the handle and adjust the dies so they just touch just like the directions say, then raise the handle and give it another 1/4 or half turn. when you lower the handle you should see the top of the drdt2 flex just a little. Just play around with it and you will get it, but it sounds to me like an under dimple.

dimple dies

use the 3/32

It sounds like you gave it the old try without instructions and got yourself frustrated! I would suggest that you find someone in the area to come over and help you get started on some scrap pieces of metal. The EAA web site lists technical counselors and chapters in your area. That would be a great place to start.
In regards to your experience with the dimpler, it really is not possible to overdimple a hole. The die set will determine the shape and depth of the dimple. You should set the tool so that the both surfaces just touch each other. Make sure you are using the correct die for the rivet and the hole you have drilled is also correct for the rivet size. Go to the EAA website and download the drill size verses rivet size chart. Your dimple die set may have come with dies for both rivets and an screws. Make sure you are using the correct die set.
To set the pnuematic sqeezer you need to use AN960 and 960-L (thinner washer) to obtain the proper gap, that is unless you have the adjustable shank option. Once again, go to the EAA website and watch a video riveting with a Pnuematic squeezer then also download the chart on how to determine the correct rivet length before and after setting the rivet.
In regards to the pressure for your 3X gun, I use 30psi for -3 rivets and 40psi for -4. It makes it easier to control. You might also think about investing in a 2X gun for the -3 rivets, it will make it a lot easier for a beginner. The 2X gun has a shorter throw.
The best thing to do is to have someone help you out. It is not a difficult skill, it just takes a lot of practice and a little instruction and you will be on your way. Don't get frustrated, it will all come together. Go to your local airport and find an FBO that does a lot of aircraft work and ask them if they have any scrap pieces of aluminum. Take it home and practice on the free stuff. It works just as well as the tool box and you will get more practice. You should expect that you should buck a couple of hundred practice rivets before you get to the real skins!
Hope this helps! Feel free to call me if you want 314 605 7744

Hey Chris,

My wife and I built our toolbox 8 months ago. Like you, we started off not knowing anything and I nicknamed our box the frankentoolbox. Thats common I think for us newbies.

Here is a link to the adjustable shank for a pneumatic squeezer that Bill mentioned. You will definitely want to buy this - instead of adding washers to your squeezer to change the length you just unscrew/screw this thing in to change the size. http://www.averytools.com/prodinfo.asp?number=274
The squeezer can do a very good job at rivets and dimples. Its a matter of making sure the squeezer has 90 psi air and then setting the right gap size.

Here is a link to the hints for home builders EAA page. We found this to be very useful when we started. http://www.eaavideo.org/channel.aspx?ch=ch_hints

The VAF community is great and you will always find advice and encouragement to get you through. Stay with it

Thanks for the post....

I'm not there yet, but expect to have all of these questions. I hope to take a SportAir class.

Chris,

The "RV Builder Basics" video might help you, too.
http://www.homebuildervideos.com

[Disclaimer: I'm the producer...]

Bowed Sheet

Regarding the dimples creating a bowed sheet, this will happen from time to time, particularly on small sheets with dimples near the edge. The dimple is stretching the aluminum, and creating radiating stress patterns. If the holes are close together the stresses add up and the sheet will have shallow bends. We see this a lot at the Airventure sheetmetal workshop.

In most cases the part you are attaching the sheet to will be more rigid, so the slight curve will disappear. You can try an simple edge straightener or roller to take out the bend.

You might want to contact someone at the Scotia EAA Chapter, http://www.eaa1051.org/

One other thing

At some point you'll try and squeeze a rivet (especially a longer one) and it won't squeeze all the way, so you'll close the gap more and try again and it still won't squeeze, then you'll close it even more and it STILL won't squeeze.

Here's what's happening. The pneumatic squeezer has a two stage squeeze if the gap is too small, the tool can't produce an adequate second stage squeeze. It is counter intuitive, but when your squeezer won't complete the squeeze you actually need to open up the gap and it should work fine.

By Jove............

I think I've got it

I picked my second tool box kit up from the Post Office last night. I got to work on it this afternoon and again tonight. WOW, what a difference a few weeks make!

I've been using my first tool box kit as a practise riveting/dimpling test case. I've been drilling holes in the box and then practising dimpling and then riveting. I could really see a difference tonight in the quality of my dimples, and the rivets as well.

I also figured out how to use my pnuematic squeezer for dimpling, as well as riveting, so I was happy with that. Out of 22 rivets I set with the squeezer, only 2 had to be drilled out.

One thing I did notice was that for the rivets I set with the gun, the gun was leaving marks on the metal. I'm using the swivel flush set from Plane Tools on my gun. I think it is the rubber piece that is leaving the marks. Any ideas how to counter this?

Cheers

Chris

Congrats on the tool box

Congratulations on your success with box #2.

If the marks are from rubber, you can rub them out with MEK or acetone.

Keith

I actually do not like the swivel head, I prefer the shortest shank I can use. It seems that the longer the shank the harder it is to control the gun. My favorite I found used at a surplus place in town was from the local Boeing plant. It sounds like you are coming along with the practice. Soon you will be on to assembling your parts!