Brief Description: Rivet L-Tank Bottom Ribs to Inner Ribs
18-5: Step 10: Rivet L-Tank bottom skin to inner ribs. Tried a new technique to rivet the bottom skin to the ribs by cleaning Proseal from the rivet holes in the usual manner for all skin rivet holes so as to not push the useable cure time of the Proseal mix used to seal rivets. Second, Prosealed holes in the usual method, wetted rivets previously cleaned in MEK with Proseal, inserted and wiped excess sealant from around the rivet with a dry paper towel so as not to dillute or wash away sealant with MEK. My thought is that I'm hammering through the sealant and not getting the rivet set as deep as I expected. And, I got a better rivet set overall, noticeably better.Maybe it was just me getting better at driving rivets but I think it was the layer of sealant I hammered rivets through that prevented a normal set. Anyway, I prefer this process. I noticed back riveting of the shorter bottom skin stiffeners did not pull down as well either but seemed satisfactory. We'll see if they leak!
After this limited tank sealing experience, I will build my next set of tanks different. I elected to use the Cleavland Tank Rivet Dimple Dies on my wings and the 4263 Substructure Die for Ribs. Together the upper and lower rivet fit well but I think the tank dimple die is too deep for the rivets. They set quite low and I think some of my rivets, although sealed well, will ride high and not provide the necessary mechanical rivet-skin bond. Time will tell. I'm thinking the same as Dan Horton.I'd like to have a substructure die for a normal dimple die.
This is what I used. I think you may want to reconsider before using the same.
This shows the bottom skin rivets that set deeper than the top by wiping sealant before driving.
An example of shop heads on bottom skin after bucking.