Countersink, Debur and Dimple Firewall #2 - 3 hours

Fairly easy night in the garage. I deburred all of the parts and pieces. Made sure all edges where cleaned on the 3M wheel. All pieces are countersunk, I made sure to countersink slightly shallow and not too deep. I’m quite happy with the result.

Finished match drilling firewall #2 - 4 hours

Never missing an opportunity to drill on the drill press whenever I can. I match drilled as much of the #30 holes on the drill press that I could. Yes a slow process....but they are perfect.



I am pondering drilling pilot holes for the engine mounts now as it is incredibly easy to do on a drill press now.A few things come to mind about doing it now; 1. The firewall has pilot holes for the engine mount already. 2. It is extremely easy to drill those pilot holes on a drill press now before I mount the firewall to the fuse. 3. According to some build logs, it seems folks have used the firewall pilot holes as a mounting point for the rotisserie. 4. I really, really don't want to try and drill those holes by hand down the road.

Before I do anything I will pose the question to the builders group to see what the general consensus is.

I finished the rest of the match drilling using the palm drill and the ATS drill guide.

All I need to do now is countersink the angles, debur and clean things up and I will be back on track!

Finished drilling F-601J angles and F-601P spacers - 4 hours

Another tedious day in the garage. Managed to finish drilling the F-601J angles. Lots of back and forth; Fitting to the firewall, clamping, checking, removing, adjusting drilling.

One item that I've decided to drill at this point was the pilot holes for the F-772B stringers. I've omitted the holes on the original firewall thinking I would drill them in the assembly as directed on the plans. However drilling these nice a straight will be challenging. After confirming that there won't be edge distance issues on my original firewall....I opted to drill 1/8" pilot holes now allowing for an easier go at it later.

Next I need to work on finishing the F-601P spacers.Careful work is needed to round the corners to get a good fit.I can then drill the first #30 hole.

Re-clecoing the assembly I can then check alignment of the spacers with the rest of the assembly and then begin drilling the rest of the #40 holes.

Started fitting firewall #2 - 4 hours

Well, I'm diving into firewall #2. I quickly noticed that I cannot get clecos into the engine mount brackets due to the powder coating. So I set up the drill press and I opened the holes with an 1/8" drill bit. At least I can cleco those holes allowing my to use a #30 later.

After all the drilling was done, I could cleco all of the engine mounts to the firewall.

Next step I shaped the top of the F-601N stiffeners to next into the F-601L angle. Slow and steady makes for good work and fit.

I double checked the fitment of the F-601D and F-601N angles. Made very slight adjustments here to ensure rivet holes line up.

All done and clecoed.

Next I need to work on drilling the F-601J angles. Now this is not the most fun part and I find the process for getting it right quite tedious. I have started by using scotch tape to place the gussets and spaces that are located under the angles. Then I carefully clamp the angles on the the bulkhead checking for proper spacing (3/32" below).


Once clamped, I flip the assembly over and use the drill to start a pilot hole in the backside F-601J angles. This way I can ensure proper edge distances before I drill through. Once I am happy everything looks right, I can then complete drilling holes to 1/8" on the drill press.

My replacement firewall arrived - 1 hour

Well...my third replacement firewall arrived. You know the one that I wanted perfect!

UPS had other ideas of what it should look like. Despite the many stickers indicating fragile it was obviously placed on the bottom of a big box. I pulled the firewall out of the box (which vans did really well) and it was bent all over the place.

The flange one the bottom was particularly bad.

I tried my best to straighten it. But the result is that it then bows the firewall.

The only way to fix that is to flute the flange.
 
Well that's an ok fix. But then I tried to take out the rather large dents in the face of the firewall, and its just not happening. I compared the firewall #2 to this firewall #3 and the #2 is in much better shape. Looks like I completely wasted my money on scrap stainless steel.

Started in working on the 2nd firewall - 3 hours

After much delay, I decided I better get going on the plane. I've let many excuses creep in and stop me building. The cold weather is one excuse for sure as I really like to build with the garage door open and the sun pouring in, and this has been a very cold spring.

My firewall situation isn't sitting well with me. I've repaired the stainless steel as best I can and refinished it, as well as I tried to take some of the small dents out. But I still want a perfect firewall (The firewall is cheap, but the exchange rate and shipping isn't) a $114US firewall is about $300CDN landed to my door. I ended up ordering a new firewall (my third now) as I want it perfect!.

No reason why I can get started on on firewall parts. Specifically I fabricated the F-601P spacers and the F-601J angles. I also cleaned up the edges on all of the other firewall pieces


I'm really happy with how these F-601J angles have turned out.