Dimpling question

Hi Guys

So I have just completed dimpling the skins for my RV4 Horizontal Stab, and now it is time to dimple the rib and spar flanges using my squeezer. My question is do I just dimple these flanges normally? My worry is that will a normal dimple accept the dimple on the skin(will it be deep enough), as in will the skin sit flush on the rib flange when riveting?

I have read of Guys running a deburring tool on the flange dimple to make it slightly deeper and also of Guys using fuel tank dimple dies on the flange to give a slightly deeper dimple.

Any advice would be greatly appreciated

Thank you

The substructure / Tanks dimple dies are a nice touch and may improve the finish a little. However, the regular dies will work. The parts will nest when the rivet is driven, but there can be a tiny bit of puckering on the surface compared to the other approach.

If you purchased good quality spring-back dies, the difference is negligible. The cheaper dies will be more noticeable.

I have both substructure and tank dies, I like the tank dies for sub structure better because they are not as deep and still give a slight interference fit, I only us the sub structure dies on thicker material like rear wing spars or where there are three layers of dimpled material, That's what works best for me anyway.

Or viewed from another angle......

RV's have been built for many decades (including award winning and grand champion examples) with just one set of quality dimple dies (literally thousands were built before the option of different sizes were even available).

There is no structural deficiency by using the same dies for multiple layers.

There are potential structural deficiencies that you can inadvertently induce if you start countersinking dimples or using other sized dimple dies and do it incorrectly.

I spent cople of weeks on this finally i made my own set for understructure 110 degrees but if you dont have this option i woulf use standard set 100 degrees from clevland for understructure and Avery for top they are soooo diferent

Thank you so much guys, all the help is appreciated

I recently riveted the entire tail section of my RV-4 and used the same dimple dies from Avery Tool (Aircraft Tool Supply brand I think). The finish was impeccable in my opinion without any "puckering". Back riveting the skin/stiffeners results in a perfectly flush, beautiful finish. Riveting with a gun and bucking bar using proper technique is very close. I was very happy with how it turned out and as Scott said, most early RVs were built this way. I've heard mixed reviews about substructure/tank dimple dies.

One thing is for certain, we aircraft home builders LOVE tools... even when we don't necessarily need them

Thank you Northern