jmbrwn

jmbrwn

Well Known Member
Well guys, I've made my first big error. I'm embarrassed to admit it, but last week I countersunk my tank skins. Then a day or so ago, I dimpled my tank baffles!!:eek: I think I had my head up my arse:mad: Anyone else willing to admit doing the same? Should I order new tank baffles/ ($25 each)? I've thought of smearing extra proseal into the dimples, but am wondering of tank leaks...plus does this compromise the baffle strength? Any thoughts?
 
Having just closed up my tanks, I can't say that it would be a standard or acceptable practice, but I think I would simply undimple the baffles:)
 
I vote order new baffles. There is some real stress in this neighborhood. Many of us would be surprised at what a couple hundred pounds of liquid can do to such structures. Plus, I'm sure you really don't want to have to redo them after the black death is applied.
 
I would be willing to bet after the MC-236B2 cures the tank would stay together without the rivets. So, I guess you could smash them flat with flat dies and build on.

Would I do that? ........ no.

Filling the dimple with seal is not ok. The rivet will not set correctly.

I would order new parts.
 
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I vote you Un-dimple

Hi Jim,
I'd un-dimple the ribs with flat dies.

To dimple and un-dimple one time... I don't think it hurts a thing.
You can still barely see it, but yours will be hidden forever!

You might want to match drill once more after that. You don't want the rivets hard to slip in the holes when you have proseal everywhere.

I agree with asav8tor, that the rivets won't set correctly if you leave the ribs dimpled.

Keep going!
Mark
 
I would think piece of mind would be worth the $50 plus shipping. As one poster said earlier, that fuel can be quite heavy after a while, especially the bottom flange dimples.

Order the new ones and fugeddaboudit!!:cool:
 
Thanks for the quick replies, guys. I think undimpling once would probably work...but I don't want to be thinking of that everytime I'm doing acro. Will continue sealing thru the weekend and make a decision Monday. The $50 bucks doesn't bother me as much as the shipping cost will wind up being!:mad:

Jeff...you must be a night-owl man!...02:17AM!!!;)

Mark...where's the pics, buddy!?!? I know you're close to flying!
 
jmbrwn said:
Well guys, I've made my first big error. I'm embarrassed to admit it, but last week I countersunk my tank skins. Then a day or so ago, I dimpled my tank baffles!!:eek: I think I had my head up my arse:mad: Anyone else willing to admit doing the same? Should I order new tank baffles/ ($25 each)? I've thought of smearing extra proseal into the dimples, but am wondering of tank leaks...plus does this compromise the baffle strength? Any thoughts?
Click to expand...


Ok, why would you buy new tank baffles. You did those right. Your problem is the skins, you DON'T countersink them. It says in the plans, dimple the skins and ribs. You don't want to countersink the skins and then have a flat surface between the ribs and the skins, strength is gone. Order a new tank skin, dimple and then assemble with proseal.
 
Not sure about the 8, but the instructions for the 9 say to countersink the skin for the skin-to-baffle rivet holes.
 
On the -8, you countersink the tank skins and leave the baffles flat...ala, no countersink or dimple. Thanks for all replies.
 
RV8 Tank Baffle

Allbee - sorry mate but you're wrong. Drawing 16A grid C7 for the RV7/8 states that you countersink the skin.

Jim - In the UK we have an inspector who oversees the build and with this problem I would first contact him. Do you have an EAA counsellor to consult locally? Secondly have you spoke to Vans support for their view?

I can't offer you my advice as I feel that as this is my first build I don't have the engineering expertise.

Bob Ellis
www.rv-8.co.uk
Wings just about finished.
 
I was looking in the manual in print, it says in the 7A, section 7. page 7-6 about 3/4 way down. Dimple skins and ribs. also has a date in the lower left. 3/2/06. All I know is I dimpled everything and it is sealed and not leaking, looks great.
 
Baffle....

In my earlier post I saw baffle and was thinking Jim had dimpled the ribs.
The ribs are baffles also;)

The rear baffle plate needs to have the tank skins countersunk and the baffle itself should remain flat. If you dimpled both it would be difficult to get the rear baffle to pop down in place. It's hard and stressful enough as it is with all the proseal oozing everywhere!

I would still just flatten the dimples and move on.

Mark
 
I ended up dimpling everything, the back plate as well. Everything went together just fine, a none event. If that is the part in question, the back plate, you can flaten the dimples, won't hurt anything. If you have the DRDT than just put the flat dies in that you use in your hand squeezer to do the flat rivets and flaten away. If not use the hand squeezer. Again, I'll say, dimpling is stronger than countersinking, if you can do the dimpling go for it.
 
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