Dimple question

[tshort]

Just started dimpling the VS skin with the pneumatic squeezer and noticed the following "ring" around the dimple:



Is this something others have experienced? The face of the male die is smooth and I can't see any real cause for it. Obviously it will go away when prepped / painted, but this didn't happen on any of the dimples we made in the builders class...

Thomas[/img]

[Wicked Stick]

Just started dimpling the VS skin with the pneumatic squeezer and noticed the following "ring" around the dimple:

Is this something others have experienced? The face of the male die is smooth and I can't see any real cause for it. Obviously it will go away when prepped / painted, but this didn't happen on any of the dimples we made in the builders class...

Thomas[/img]

TShort,
This ring is normal, in fact I'd be a bit worried the dimple dies didn't squeeze down far enough if you don't have the ring. Be cautious though, you don't want a HONKING ring there.. just a slight reference of it's existance.

To properly set up the dimple dies in a pneumatic squeezer, you should just be able to spin/turn the die when you close them together in the squeezer without any skin/material between them.

Do you have the adjustable shaft on your squeezer ? If so, that makes life much easier. What I do is install the dimple dies, activate the squeezer and adjust the shaft so the dimple dies touch each other but I can still spin them slightly. Then I know I have it set. Just be carefull you don't have the shaft extened too far when you first put them in and squeeze them together. Also, watch those fingers...

[Spike]

Looks good to me

[tshort]

Yeah, the adjustable shaft is nice. I checked the travel and I'm not near the last threads.
Re: the adjustable shaft - do you guys find that the flat side of the part that goes down in the sueezer (the part that maintains its orientation) doesn't stay in the correct spot? Mine will wander 30 degrees or so to each side, out of the "channel"
Don't know if this is unique to my squeezer or a common issue.

Thanks for the posts! - I'll get back to dimpling now (gets almost as monotonous as deburring - you have to watch yourself!!)

Thomas

[captain_john]

OMG!!!

Not dimple halo's!!!



j/k, but if you want to mitigate those marks, chuck the dimple die in your drill press and hold a slice of scotchbrite against the face of the die. It will smooth it and keep it from piching the metal when pressure is applied.

CJ

[Guest]

Regarding adjusting the pneumatic squeezer for dimpling, I ran a test. Took a narrow strip of AL, drilled a bunch of holes, & I even deburred them. Then set the gap between the flats of the dies equal to the thickness of the metal strip. Dimpled 4 holes. Tuned the dies 1/2 turn closer, dimpled 4 more holes. Repeated until the dies touched when adjusting them. Most of the strip of metal ended up in an arc. Which adjustment did NOT cause a curve in the metal?
The one where the dies touched left the strip straight.
All other adjustments distorted the metal.
So I always adjust the squeezer so the dies touch and I don't worry about the halo.

[mustang]

Yes, and I have recently discovered that if I leave the blue plastic on until after dimpling, the dimples look much better with no halos or other marks.

You might wonder about deburring, but the top side will not need it if you leave the plastic on, and the bottom side will have the plastic removed already so you can debur that side which is the worst side anyway.

Cheers, Pete

[Wicked Stick]

Yes, and I have recently discovered that if I leave the blue plastic on until after dimpling, the dimples look much better with no halos or other marks.

You might wonder about deburring, but the top side will not need it if you leave the plastic on, and the bottom side will have the plastic removed already so you can debur that side which is the worst side anyway.

Cheers, Pete

Pete,

I'd strongly recommend against that. You should remove the plastic on BOTH sides before debur and dimpling. All to often you could end up with small pieces of aluminum under the plastic and you don't want to dimple them into the skins surface.

If you want to keep most of the skins safe with the plastic left on, then use a soldering iron (smooth the tip first) and a straight edge and you can draw/melt a line in the plastic about 3/4 of an inch on each side of the holes, then simply peel off the strip and you have a nice straight peel, with no scratches in the skin. Don't use a razor blade to do this at it will cause a deep scratch. Just use a very light pressure on the soldering gun so it almost melts it through. (you don't want it to melt all the way through, but just enough so it peels/tares off nicely.

Very minor surface scuffs and scratches are no big deal really if you plan to scuff the aluminum and prime it.

[mustang]

Dave,
Well, thanks for the caution. My friend who advised me on this process is now building his sixth RV and has even built a retractable "Four" so he must know something. Anyway, I tried it and so far the results are better than removing the plastic first. I do use a soldering iron to remove the strips down the rivet lines. Now, I do it after drilling and dimpling. BTW, he does no deburring on the drilled out holes whatsoever.

Cheers, Pete