I was floored by yesterdays outcome. Really took the wind out of my sails. I really hate the taste of defeat. It's easy to dwell on the negative I suppose. But...The bright side is that I did not rivet anything yet. So...Not a complete loss.
I called Vans this morning to talk cracked dimples. The conversation was...interesting. The answer is not black and white. Start over, or build on. Vans thinking is this....Its your choice what to do. Replace, or keep going. At the end of the day, what are you comfortable in doing.
One way to look at it is that cracks are not a good thing. But....this area in particular is prone to develop cracks, due to how much pressure the skin is under to form the dimples. So as far as Vans was concerned....Its up to me how to proceed. He did indicate that in his personal observations he hasn't seen a crack propagate out of the screw hole. Not to say it doesn't happen, its just that he hasn't seen it yet.
So...Now. Personally what do I want to do. Well, as much as it sucks... New skins are on order.
The question is how do you avoid cracks. Again...I asked Vans how they felt about the various options that some of the forums discuss. I asked about drilling to #18 or #17, then dimpling. I was surprised that he did not feel this was a wise course of action. His opinion was that opens the door for the dimple and hole to be out of alignment. This could cause the screw to sit improperly in the hole, which in turn can cause issues of their own. He didn't say no, but I could tell if it was him, that's not his choice. He did feel that the #19 hole was the correct course of action. I had also asked him about quality of dies and he did not feel that this was important. As long as the dies are cleveland, avery, plane tools, etc. I should be fine.
He did say that hole preparation is the key. He recommended polishing the hole....Really do my best to alleviate potential stress points before I dimple.
In talking with friends, some mention drilling the hole larger, some don't. One suggestion that seems very logical is to lube the dies to help the skin from being "grabbed" by the die. Mineral oil is suggested. Maybe WD40 will work.
Well...I know this. I have a TON of material to practice on with two botched tank skins. I think mentally I have to be prepared that I may end up with a crack. My goal....is to minimize this as much as possible.
New skins are set to arrive on Wednesday and a #19 reamer will come shortly as well. So I will do every sort of dimpling scenario in efforts to prove to myself how to dimple the thick material and not crack it. When the new skins come...I will dimple first, and then worry about all the match drilling and countersinking that I have to redo.
