What's new
Van's Air Force

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

First mistake: Drilled 1/8th holes in hs spar web

readf

I'm New Here
I JUST started building and already made a mistake. I was following the instructions line by line, and when told to match drill 1/8” holes with the spar web and the spar caps, I did not think to check the river schedule later on to see if ALL the holes are 1/8”. Sure enough, after drilling, deburring and clecoing everything back together, the next instruction is to match drill the back of the web with a #40. Can I just keep going and use a -3 rivet instead of a -4 in that spot?
 

Attachments

  • 5C3A2C3E-95A6-45ED-847C-37E5F1E419E0.jpeg
    5C3A2C3E-95A6-45ED-847C-37E5F1E419E0.jpeg
    107.3 KB · Views: 290
Last edited:
Are you asking if you can put a -3 rivet into a hole drilled 1/8 (aka #30 drill). ? The answer would be no. Can you use -4 rivets in those holes that you opened up? That’s probably what Vans will allow, but a call to them (or replace parts) is the prudent way to handle it.
 
My advice is to thoroughly read the complete section a number of times before starting any work on that particular section. Get familiar with what’s going on and why. When you have a good solid mental picture of all the steps, and where they lead, start work. Sometimes I have spent a couple of days reading and rereading a particular section before it really makes clear sense to me. Maybe I’m just a bit slow, but it’s better than waiting for replacement parts. And shipping them to Australia.
Cheers DaveH
120485
 
Are you asking if you can put a -3 rivet into a hole drilled 1/8 (aka #30 drill). ? The answer would be no. Can you use -4 rivets in those holes that you opened up? That’s probably what Vans will allow, but a call to them (or replace parts) is the prudent way to handle it.

Yes, the question is really “can I just upsize the rivet to the hole I drilled”. I emailed vans as well. Feels like it’s a long shot :-(
 
My advice is to thoroughly read the complete section a number of times before starting any work on that particular section. Get familiar with what’s going on and why. When you have a good solid mental picture of all the steps, and where they lead, start work. Sometimes I have spent a couple of days reading and rereading a particular section before it really makes clear sense to me. Maybe I’m just a bit slow, but it’s better than waiting for replacement parts. And shipping them to Australia.
Cheers DaveH
120485

Thanks Dave,

Yes, this is pretty clear now.
 
One trick I learned from taking the Synergy Air empennage class when starting my build is to look at the rivet call out diagram and then use a sharpie to label the rivet holes with the rivet size before drilling/driving. Don't need to label each hole, just a line along side the holes with the rivet size next to it. This causes you to read ahead to be sure, and helps speed up the actual drilling/driving as you don't then need to go back to the drawings frequently to be sure you are using the right drill or rivet. You can then wipe off the sharpie marks with acetone after you have finished that row of rivets.

Just a suggestion that helped keep me from making a bunch of mistakes.
 
Wait to see what vans says but i seriously doubt you will have the edge distance on -4 rivets if i am picturing it correctly. i think you’ll have to replace the spar/cap.
 
Yes, the question is really “can I just upsize the rivet to the hole I drilled”. I emailed vans as well. Feels like it’s a long shot :-(

You originally asked about installing a -3 rivet in a hole drilled for a -4. The -3 rivet is smaller (3/32) than a hole drilled for a -4 (4/32 or 1/8) rivet. The drill for a -3 is a #40 drill, while a -4 rivet gets drilled with a #30 drill. I believe you meant to ask about upsizing the rivet to match the larger hole, but originally the way you phrased the question, you sounded li,e you wanted to put the smaller -3 rivet in the larger hole.

Confusing enough? Lol call to vans is in order to se what they recommend. If you have to replace parts, don’t order anything yet.. move on to the other parts, so incase you make more scrap metal by accident (we all do it) you can combine shipping!
 
Trying to help

I have been looking at this since you posted the questions and I still can't quite understand where you made your mistake in drilling?
You are referring to the web of the spar where "I believe" most rivets are -4's.
What I see in your picture is the flange drilled to accept -4s. evidenced by the #4 clecos.
The holes in the flange are supposed to be #40 drilled to accept-3 rivets.
One or two of those might be acceptable but probably not the whole row.
Maybe you can share some more insights and perhaps a couple more pics??
Learning to deal with a mistake is just a part of the journey, pick up another part of the kit and work on it until the issue is resolved.
 
Hole size

As mentioned before. Always look at the fastener callout on the plans. Rivets, screws or bolts. You will be surprised how often there's a mix of hole sizes.
Good news is that's not an expensive part and it can be used later for a non-aviation function. I used to bent flap spars to build a really cool plans easel. :D
 
The part is inexpensive, but it’s 11 feet long so freight shipping is required. I have elected to use nas1097 reduced head rivets in similar situations as suggested by other builders. Of course each situation warrants careful analysis and yours may not allow for this. The hs spar flanges are wide enough to use a -4 but all those rivets will be in skin so the larger head is probably unacceptable, hence the reduced head. Then the concern for me would be if a reduced head rivet has enough surface area on a 3/32 dimple through an 1/8 hole if that makes sense. You will lose 1/64 of material to grip all the way around under the rivet head.

Alternatively, could you just use -4 rivets and be good with that through the skin? I don’t know, what did vans say to do?
 
Actually, now that I’ve looked at the picture what you show is vs spar, not hs. That should be an easy to ship item.
 
Actually, now that I’ve looked at the picture what you show is vs spar, not hs. That should be an easy to ship item.

Ah, yes. It IS the vertical spar. In my original message I got pretty much every detail wrong it seems. I’m new! lol Vans has yet to reply. They are all busy with Oshkosh. I’ll likely hear back tomorrow. I’m fairly confident I’ll be starting it again given the edge clearance remaining.
 
I have been looking at this since you posted the questions and I still can't quite understand where you made your mistake in drilling?
You are referring to the web of the spar where "I believe" most rivets are -4's.
What I see in your picture is the flange drilled to accept -4s. evidenced by the #4 clecos.
The holes in the flange are supposed to be #40 drilled to accept-3 rivets.
One or two of those might be acceptable but probably not the whole row.
Maybe you can share some more insights and perhaps a couple more pics??
Learning to deal with a mistake is just a part of the journey, pick up another part of the kit and work on it until the issue is resolved.

Thank you for the reply! Tomorrow I’ll take a few more pictures and take time to re-analyze. In my frustration and haste, I don’t think I explained it properly in my first post.
 
Min Edge spacing for countersunk rivet is 2.5x diameter of rivet shank, so to use -4 you need 5/16 inch measured from the center of the hole. If have that much then maybe they are okay with it.
 
Last edited:
Min Edge spacing for countersunk rivet is 2.5x diameter of rivet shank, so to use -4 you need 3/8inch measured from the center of the hole. If have that much then maybe they are okay with it.

I suspect I’ll be too close to the edge. I’ll follow up with what they tell me though.
 
Min Edge spacing for countersunk rivet is 2.5x diameter of rivet shank, so to use -4 you need 5/16 inch measured from the center of the hole. If have that much then maybe they are okay with it.

Good reminder, this bears repeating.. most new builders thing edge distance is the aluminum remaining to the edge, but it’s actually measured from the center of the hole to the edge!

Another comment that deserves attention was to use NAS 1097 “Oops” rivets. They are only acceptable in one ot two at a time, not the whole row, so don’t think that’s acceptable. (I don’t recall where I heard this though)
 
I measured today, and you will definitely not have the required distance to upsize those rivets. Curious to hear what Van's comes back with, but I would bet it is a no go.

If it makes you feel any better I had to order 2 replacement parts last week, not great.
 
I effectively built the VS twice after ordering and reordering messed up parts. It takes time to learn and understand what and how Vans is telling you to do something. And realize how many different ways you can screw something up. Even if you understand what they are telling you to do, poor technique will cause frustration and the only way to learn is by screwing up a few parts.

By the time you get done with the emp kit you will improve tremendously, quality will improve, and mistakes will happen less often. I'm just about done with the emp kit and have spent about $900 on new parts and shipping. It's part of the process.
 
Use reamer

Just a suggestion to the OP and anyone else new to building. If you use a reamer to open out pre-punched holes it is a lot harder to make a mistake like this. A drill bit will make short work drilling out any pilot hole, but put a #30 reamer in a #40 pre-punched hole and the mistake will be immediately obvious! Not sure if this applies here, perhaps they weren’t matched holes, but applies in many situations.
 
Back
Top