dan
Well Known Member
When I built my RV-7 tanks, I dutifully scuffed the alclad off the skin where ribs, stiffeners, etc. mate up.
Now I'm building my RV-10 tanks and considering skipping the scuffing. I'm trying to grok a tangible benefit.
All the tanks I've seen online where builders scuffed the skin -- they don't scuff the *opposite* surface. Just the skin. The rib flange, the stiffener face, etc. weren't scuffed -- plain old undisturbed alclad on those. And if you get right down to it, I've never seen anybody scuff the area around dimples where we surround each shop head in sealant. Hm. Maybe these omissions are down to oversight on the builder's part?
Or maybe all this scuffing is much ado?
My thinking is -- if the sealant is sandwiched firmly between the skin and the other part, where's that sealant going to go? Is there really a chance of it debonding in that tightly mated area, and working itself out somehow? And is scuffing going to make the difference?
Or is scuffing more about giving the fillets and overlap in surrounding areas better grip?
I don't mind taking the extra effort to do this scuffing business -- as I said, I did it on my RV-7, and I've had zero leaks. It's not difficult, and it's not even that time-consuming. But I'd like to understand something rather than just do it blindly. Can you help me understand this better?
Now I'm building my RV-10 tanks and considering skipping the scuffing. I'm trying to grok a tangible benefit.
All the tanks I've seen online where builders scuffed the skin -- they don't scuff the *opposite* surface. Just the skin. The rib flange, the stiffener face, etc. weren't scuffed -- plain old undisturbed alclad on those. And if you get right down to it, I've never seen anybody scuff the area around dimples where we surround each shop head in sealant. Hm. Maybe these omissions are down to oversight on the builder's part?
Or maybe all this scuffing is much ado?
My thinking is -- if the sealant is sandwiched firmly between the skin and the other part, where's that sealant going to go? Is there really a chance of it debonding in that tightly mated area, and working itself out somehow? And is scuffing going to make the difference?
Or is scuffing more about giving the fillets and overlap in surrounding areas better grip?
I don't mind taking the extra effort to do this scuffing business -- as I said, I did it on my RV-7, and I've had zero leaks. It's not difficult, and it's not even that time-consuming. But I'd like to understand something rather than just do it blindly. Can you help me understand this better?