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wrongway john

Well Known Member
Here are two pics of a piece of the RV tool box I?m making. I did about half the dimpling using the C-Frame, and the other half using the 3/32nd dimple dies set up in the hand squeezer.

I?m curious as to what is causing the very slight O-ring scratch around the hole. The dies don?t appear to visibly show a ridge, nor am I able to feel it, but I assume this must be what is causing it. I wasn?t hitting the C-frame that hard, and tried hitting softer and softer. Hand squeezer did the same thing. As you can see from the pic, I sanded out a handful of of the O-ring scratches to see how deep the scratches were, but would still like to make a nice dimple without having to sand this out. All of my equipment is new including my dies from Avery. When I took the Sport Air course last year, all of their old equipment didn?t cause these O-ring scratches. Any suggestions?

On the second pic, I wanted to show what tool I?m using to de-bur. It?s a new tool, and I?m giving each hole two light twirls, trying to take off the minimum amount of material. It wouldn?t show up on the pics, but this tool is leaving serrated edges around the hole. It?s even clearer under a magnifying glass. It just doesn?t look right, and it seems to me this could easily cause cracks especially after banging rivets in.

I tried using a larger hand drill to de-bur to, but it was no better. similar Do some just hand sand the area?

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Not to worry . . .

The rings around the dimpled holes are perfectly normal. They are just a mark, not a scratch.
Gently wiping with a piece of scotchbright will remove any burrs, especially on skins. I used the same deburring tool, but rarely on skins.
 
Not too bad

John

Given that I'm only seeing a picture and not the actual dimple, it doesn't look too bad. My DRDT dimpler would leave a little ring every once in a while put it was so minor that when I would use a scotch bright to scuff the part up for priming, it would remove the ring.

As far as the deburing goes, if the hole you are deburing is larger than the pilot of the dubur tool, sometimes I noticed it would "ratchet" back and forth on me an leave the serrated edges you are talking about. I use the weldon speed deburr bit a lot. This guy leaves a really nice finished touch to a hole.

Mine came with the planetools kit that I bought. It's item number 43 on this page http://www.planetools.com/NEWRVKIT.htm

Good luck, hope this helps.
 
The O-ring mark isn't too big of a deal for me, just prefer not to have to sand it out and for it not to leave any mark at all.

The deburring of thin sheets with this tool is a bigger concern for me on these #40 holes. DGlaeser, what did you use on the thin skins then, since it wasn't this tool? Marchudson, I'll look around some more for that tool and others, and see if I might be happier with those.

I remember seeing another post from someone who once showed some pics of cracks occurring around dimpled holes after he banged his rivets in. Although I don?t think it was brought up at the time, those cracks look very similar in the pattern formed after deburring with this particular tool because of the serrated edges it is leaving.

Just not liking the way these holes look at all after I debur them. I can see these edges up close with the naked eye; with a magnifying glass it highlights it better.
 
Deburring skins

I either wiped them with a scotchbright pad (before dimpling) or did nothing. If you can run your fingers over the holes (lightly) and not feel anything, then there either isn't a burr or not enough of one to worry about.

Regarding the marks from the dimple tool - dimple a piece of scrap (whack it as hard as you can and leave a mark) and then just spray a light coat of primer on it. You won't see a thing (at least I never did).
 
Dennis, I'll do just that and work on it some more on some scrap pieces.

I'm thinking on these thin sheets, I'll feel more comfortable just doing a light scotchbrite pad wipe as well on these holes. If more people could see what they look like with that standard tool under a magnifying glass, I think more would reconsider it as well.
 
DGlaeser said:
wipe them with a scotchbright pad (before dimpling) or did nothing. If you can run your fingers over the holes (lightly) and not feel anything, then there either isn't a burr or not enough of one to worry about.
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I agree, this is the best method. If you use a reamer to enlarge the hole, rather than a drill bit, there will be very little burr and it can be wiped with scotch brite. The three flute deburring tool we don't recommend. The multiple flutes are always bouncing around trying to decide which of the cutting blades to engage. If you use a single flute, or high hook, or 'one hole' deburring tool then there is only one flute on the material at any given time and it will not chatter. The common tendency is to remove too much material with any tool, so the scotch brite is really the best.
 
Thanks everybody for your feedback. Man, the things I didn?t learn at my Sport Air workshop.

It seems to me, deburing really shouldn?t be using a tool with a cutter, especially when the holes are this small. I tried some experimenting today.

I went to Lowe?s and bought a ?? wooden dowel. Tried several combinations of things. One was cut some 400 grit sandpaper in a conical shape and glued it to the dowel after running it through a pencil sharpener. Rubbed the wooden dowel between my hands with the other sandpaper end in the hole, and have results that I like on new holes, avoiding the other debur tool altogether. Sandpaper probably won?t last long between holes though before I have to change it out. So, don?t think I like that near as much as what I did next.

On the other holes that I already used my debur tool on, I took some 400 grit sandpaper and got rid of the serrated edges on the one side that protruded. On the dimple side that was sunken, I took another piece of the ?? wooden dowel, sharpened one end in a pencil sharpener again, cut off a very small piece of a fine scothbrite pad, poked it through the sharpened end of the dowel, put it in the dimple, and again rubbed between the palms of my hands, and it really did a remarkable job of giving me a nice hole that I?m finally comfortable with. Also used the dowel with not as sharp of a point, and a small piece of scotchbrite pad put in the dimple. Not sure which dowel end I like the most yet, both ways worked great for me, and I?ll rest easy putting rivets in those holes.

Even looking at it at 2X and 4X power under the magnifying glass all serrated edges are finally completely gone where I used my debur tool. I?m sure I?m going to skip the deburing tool altogether though, and just use the scotchbrite pad and dowel like I described. I?m really happy with the results.

And the even better news is, I understand I only have to do this 18,000 times since I understand that is how many rivets are in the RV-4. ;)
 
Just a brief update. Maybe this will help others.

RVNineA, I took your tool recommendation, and really am pleased with this little debur tool. Thanks! I ordered it from Cleveland tool, and the difference is huge compared to my 3 blade. Hole looks great under a magnifying glass too. If I wasn?t happy with this tool, I was going to try Marc?s recommendation next with the cogsdill debur tools which he gave a good critique too in e-mail. But this one is doing the job quite well. No more 3 blade debur tool for me, at least not for this application.

I did find something I could use my 3 blade debur tool for that it works great on. After I indent my hole, it?s still a little too small to keep drill from walking, so that?s where it comes in handy now. Bottom pic of the HS-409 is after the indent, and top pic is after I used the 3 blade debur tool for it right after that. It tracks very well.
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flytoboat said:
18,000 times 2 plus, because you are riveting at least 2 pieces together.
Click to expand...

Yeah, I guess you?re right. And if we count both pieces, along with deburring top and bottom, I guess we are doing this 18,000 X 4 times. Gosh, that does seem like a lot of work. Oh well, I think I?d rather still be out in my shop than in front of a TV set.
 
That's why I use a deburring bit on a hex extension chucked into a B&D electric screwdriver. It really speeds things up for me.
 
"I was going to try Marc?s recommendation next with the cogsdill debur tools which he gave a good critique too in e-mail."
I'd be interested in a critique of the Cogsdill deburr tool if Mark can post it.
John
 
rjtjrt said:
I'd be interested in a critique of the Cogsdill deburr tool if Mark can post it.
John
Click to expand...

I saved his e-mail, it was an excellent review and critique of the cogsdill debur tools that he uses. Had the debur tool I got from Cleveland not worked to my satisifaction, I was going to try those next.

Not sure if he is Marc is still monitoring this thread, I?m PM him, and see if he?ll let me copy and paste it here or send it to you through PM or e-mail.
 
Springback Dies

Wrongway....you have springback dies that leave the mark. They are meant to overbend the metal around the dimple improving the resulting surface. Scotchbrite or sanding before you paint makes them disappear.

I use a Cleaveland one flute deburring tool in my cordless screw driver. I also use that tool for countersinking holes when getting out the microstop is not worth the effort. With some practice, you get just as nice result.

I have some vids on youTube. Search Pbr47906.

Have fun during your build. Even though there is lots of frustration, the things you learn and the joy of figuring something out to the end result is very enjoyable.

Paul
LAF
RV7A SB Slider
Aft fuselage.
 
rjtjrt, check your PM. Marc rarely checks his PM, but I'm sure he wouldn't mind me sharing what he has to say about Cogsdill debur tools especially if it helps someone. He really likes his.

Pbr47906, thanks for the youtube links. I recently have been spending a lot of time on EAA videos here lately, along with a few on youtube, and really have learned a lot.

I've learned so much from you guys on VAF and these video's, and really appreciate all of your feedback. I don't have an EAA chapter within about 100 miles of me, so this is where I get virtually all of my info. Without the internet, I'd really be lost, nor would I have bothered to attempt this RV-4 build.
 
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