What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Final drill skins?

U

Ueli N

Member
Patron
I am a new builder and started to build on the tail section of the RV 12.
So far not too many problems. Rudder completed.
Something bothers me where I need some expert opinion.
In the plans and on the video there is no mention about final drilling the
skins. With my experience the rivets will not fit through the skin and ribs
without running the #30 drill through first, or at least on most holes.
It seems the holes are about 1/1000 th too small.
If the holes are deburred in the first place, there is no burr visible after
drilling.
How are you handling it?
1: deburr all holes, cleco, drill and rivet
or
2: cleco, drill, remove-deburr, cleco and rivet

Any advise please -
 
Final Drill Skins

I did not drill the skins (well, in just a few places). For me using an awl to align the holes where needed was enough.
 
i just got my kit and my experience is that the skin holes are just too small.when a rivit won't fit into the skin only, not attached to anything, the hole is not big enough. if you try a rivit on a few pieces with only that hole you will see that the hole needs a #30 [or equivelent] run thru it. it only takes a .00001 to make or break the fit.
if it won't fit thru the skin alone it is not an alignment issue.
 
If a rivet will not fit through just the skin holes then something is wrong.

Try a different rivet. Try a different hole.

I have found that some (very few) rivets are larger than others.

Calling Vans might be in order.

-Dave
 
DaveLS said:
If a rivet will not fit through just the skin holes then something is wrong.

Try a different rivet. Try a different hole.

I have found that some (very few) rivets are larger than others.

Calling Vans might be in order.

-Dave
Click to expand...

It's like Scott (from Van's) mentioned in the link I posted above. Sometimes a tool at the factory may become a bit dull and a hole won't be sized properly, but I'd bet it's rare. I didn't find that to be the case often. I had a few that seemed undersized, but who knows...I could have had a burr on the rivet, or ???
 
Always fit, Cleo, drill, disassemble and deburr. I have found that skins can and will creep on you when reassembling after good fitting and drilling. The single most often mistake I have seen builders make is not using enough clecoes. Get plenty of them and use them. On skins I go every other hole when fitting and drilling, it is important. I know it is more work, but my skins went on great and only on occasion did I need to ream/drill a hole during the final riveting. I bought a lot more clecoes than recommended, especially on the fuselage when you get to that point. This is my opinion on the best way to get a really good fit and finish. Hope this helps.

Bird
 
I would not follow Bird's advice, for the -12. I understand that the -12 skins are thinner and the practices that work well for other RVs do not all apply to the -12! My experience was that an occasional "touch drill" is needed but NOT often. Also do NOT over-deburr! Just a light turn with the deburring bit in your slow-speed power screwdriver.
 
Final drill skins

Thank you everybody for your info. I was working on the AST's today.
Using a awl seems to do the trick, with a little pressure and twist of the
wrist makes the hole just large enough to wiggle the rivet in.
Don't know why I did not think of it myself.
 
I had problems with a lot of the holes, especially when going into thicker material. I made this tool out of a piece of a #30 drill bit insterted in a mini chuck. Run it through any holes you're having touble with and the rivets will go right in. If you take the straight end of a #30 bit, you'll see it's the exact size of the prepunched holes. With this tool you don't need to worry about elongating a hole twisting an awl in it.

cjvl.jpg
 
I've not had to final drill too many holes. What I've found is that the pull rivets are sometimes oval and a simple 90 degree rotation allows them to fit. If a section doesn't seem to fit well I re-cleclo it and that seems to be enough. I use clecos in every hole. I think I have more than 500 of them.
 
I was able to use a punch to get all but a few holes correct. My fall back was to turn a #30 bit by hand, and as a last resort drill to match.
 
You must log in or register to reply here.
Back
Top