DATE: 11-07-2024 TIME: 9:27 – 1:00 ~ 3:30
Continuing the preparation of the trim tabs per page 9-17 starting at step 4, removing the vinyl in preparation for dimpling and deburring prior to priming the inside of the tabs.
As I was finishing the dimpling, which I had to do with the rivet squeezer as there was no way to get the skins under the C-Frame without stressing the final bend in the trailing edge, loyal assistant EJ showed up and helped with the masking of the foam rib locations, scuffing and cleaning.
We then took the pieces outside and sprayed them with Zinc Phosphate from a rattle can. A lot easier than mixing up P60G2.
We waited a little for the primer to dry and moved on to checking that the foam ribs for the elevator trailing edge would fit correctly, removed the VHB tape from the top of the trailing edge wedges. I had already brought boards and bricks to lay on the elevator so everything was ready there. Then we brought in the trim tabs, checked all those foam ribs, tested with the wedge clamps and got everything laid out ready to apply the fuel tank sealant. I had bought FLAMEMASTER CHEMSEAL 2.5 OZ CS3204 B2 and FLAMEMASTER CHEMSEAL 6 OZ CS3204 B1/2 sealant and was intending to use the B1/2 but ended up using the B2. I did not have a “caulking” gun so we ended up with a bit too much sealant on us, but it worked out OK and 2.5 ounces was more than enough to do both the trim tab and elevator trailing edge ribs.
Per the instructions, we clecod the elevator trailing edge together right after inserting the ribs and adding the weight, but did not rivet the closing tabs due to lack of access on the bench. We did as the manual suggest with the trim tabs, clamping with wedge clamps, clecoing the forward spar and riveting the closing tabs.
There is a bit of conflict in riveting the trim tab horns and the lower flange of the spar to the skins. There are 2 rivets common to the spar and the horns. If you rivet the spar to the skins first, except for those two common rivets, and then rivet the trim tab horns, it is easier to set the rivet that is really close to the outside edge of the trim tab horns, through the spar. On the other hand, it becomes extremely difficult to then set all six rivets in the trim tab horns as the bent upper closing tab interferes from the edge and the spar interferes from the front. I riveted the rearward 4 rivets in the horns, and then set all the spar rivets. That was pretty difficult and required opening my rivet squeezer as far as I could by winding the set into the handle as far as possible, putting it into place under the horn and then winding it up so I could set the rivet. Then moving it to the other side of the horn required unwinding the set again, moving the squeezer and resetting the squeezer to set the rivet. That was actually easier than setting the outside rivet into the spar once the horns were in place.
If I were to be presented with a similar situation, like building another RV-10, I would completely rivet the spar in place first, excluding the rivets common to the horns and spar, then rivet the horns in place. It is difficult, but you can much more easily set all the rivets properly.
Next up was gluing / fuel tank sealing the foam ribs in place in both the elevator and the trim tab ribs. We thought we were using the B1/2, 30 minute work time, sealant so we worked pretty quickly, then discovered we had used the B2, 2 hour work time, sealant but it didn’t matter. That stuff is horrible.
The bonding of the foam ribs for the trim tabs is here on page 9-17 but the bonding of the foam ribs for the elevator trailing edge is on page 9-14 starting at step 8. As of this moment, we are waiting for the sealant to fully cure.
If you take a look at the start and ends times in the EXIF data of the images you will see that from the moment I started mixing the sealant to the moment I finished riveting the closing tabs on the trim tabs was about 15 minutes so the 30 minute working time sealant would have been fine.
Being only a little after 1:00 p.m we went to work on the tail cone as described in section 10. Rather than confusing the issue, I am going to create a new post even though it was still the same date.