<August 6, 2006>
More Right Tank Rib Riveting
I didn't talk about my sealing process to much yet, so I will attempt to document it better today. Now that I have a few days experience with sealant behind me, I feel like I have developed a process that works for me.
In general my process for the ribs is to cleco the tank together, remove the rib I want to rivet, apply sealant to the rib flanges, then cleco it back to the tank and start riveting. Sounds easy enough right? I treat each rib as an individual project so I mix a new batch of sealant and fabricate new tools for each rib (details below). I am sure this has added some time, but it is a process that works for me, and I am probably not going to change it. A lot of people complain about messy clecos while riveting tanks, and while yes, they do get sealant on them, using my method of a rib at a time I used the same messy clecos on each rib I am going to rivet and it has kept the mess to a minimum so far with only about 40 clecos needed. I have yet to rivet the baffle, but I know I will be getting a lot more clecos messy when I do.
Rather than go into my process here, I will do it with pictures, so look and read on if interested.
Before starting a rib, I fabricate these three tools from $.05 tounge depressors I got at the crafts store. Actually, I make a few of each at a time, but I after each rib I throw them away and get a new set. I think you get the point. It takes all of 2 minutes to make a handful of these, so it really isn't a big deal. I don't know why but I have these in reverse order; The one on the left I use in the end to smooth out the fillets between the ribs and skin, the one in the middle I use to dab a blob of sealant to the shop head of each rivet, and the one on the right is the one I use to apply the sealant to the ribs. These and the process works for me, but YMMV.
I use clear plastic cups to measure and mix the sealant for each rib. I use clear because it allows you to see (from the bottom) how well you mix the sealant. You want to be sure that there are no pockets of white or black left in the cup and being able to inspect the situation from below is helpful. For each rib I mixed 33 grams of sealant (30g white, 3g black). So why does the scale read 44g in this picture? Well, it is because the empty cup weighs 11g.
In preperation for riveting, another rib gets a coating of sealant. You can see my dirty (sealant) clecos in the backgound. I found that when put in place, plenty of sealant oozed out of the dimples in the skin, so I am hopeful that they will seal well.
The weather has been really nice here lately, so Sonoma just lays in the yard and naps while I work. I accidentally woke her up (sorry girl) while getting in position of this photo.
I managed to get the remaining three interior ribs riveted in place today. By the third rib of the day I had my process dialed in and I was cruising right along. So far so good, with no major issues even though I was riveting solo. By the way, this picture was taken after cleaning off all the extra sealant that oozed out of from around the rivets while riveting.
Looks good on this side too. I still needed to clean up the tools and shop and then it was time for a beer!
Sealant dabbed on every shop head and a fillet along the flange skin seam... No leaks please!
After a few ribs I got much better (and faster) at making nice fillets.
When each ribs was done, this is what I had left (from 33g of sealant mixed). I just threw the cup and the tounge depressor tools away and grabbed fresh cup and tools for the next rib. That way I always had fresh sealant and the tools didn't get goobered up.
My friend and neighbor Jeff, who happens to be an A&P, brought over these cool storage racks for me to use. He just put a big new lathe in his shop and didn't have room for them anymore. I like how you can remove the tray/shelves and these should be useful for parts stoage... thanks Jeff!