MTFCA Forum

What is the best way to make holes in the cowl lacing for the rivets?

Push an awl through the lacing to spread the weave open. Don't punch a hole and break any fibers.

Cut your piece to length. You will need two pieces measured from the center of the cowl at the center hinge down to the frame.
Put your first piece of lacing at the top by the hinge bracket on the firewall, and mark each hole as you go down to the frame with a black sharpie.
I used a finely pointed and tapered punch and a small hammer, while holding the lacing on a wood block on your work bench. Punch all holes now.
You then can do your rivets up from top to frame at the firewall. Your lacing holes should be pre punched and positioned perfectly.

I made a couple of tapered awls from some messed up Philips screwdrivers. Just grind a taper on the end to suit whatever purpose. The same tool makes an excellent scriber. The steel used in the screwdriver blades is tough stuff.

Allan from down under

I used an ice pick and it worked just fine.

Also ice pick

Me too.....ice pick

Make sure you install them the correct way...

Unless you have the tank out and a helper, pop rivet them in place.

I have the gas tank out. Do the rivet heads go on the inside or outside of the cowl?

As is shown in the picture, the rivet head goes inside. You need a helper to hold the rivet head tight against the inside of the cowl with the 1/4” punch, while you spread the legs of the split rivet and curve the ends deep into the lacing so the split legs don’t click against the hood while driving. Jim Patrick

Good luck getting the two lower ones on the side riveted. I gave up and used pop rivets there.

Allan from down under.

Jim, I did notice in the picture that the rivet legs were on the outside of the cowl. I wonder where that picture was from. It looks like it could be from a manual. Maybe Tim will respond.

I wonder why the legs are supposed to be on the outside. It would seem that there would be less chance of of the hood coming in contact with the rivet if the head was on the outside.

Bruce. Just the opposite. The lacing is very firm, making it almost impossible to press the head into the lacing deep enough to recess below the surface. By the same token, it is very easy to press the split tines deep into the lacing. Also, with the head on the outside, the split tines on the inside have a difficult time seating against the inside steel surface of the cowl and will almost certainly start to rattle. Jim Patrick

PS. If you split the tines apart a little, then use a 1/4” - 3/8” round shaft between the tines and hit with a hammer, it will curl the tines down and imbed them into the lacing. The round shaft can be a screw driver or a small socket.

Jim, Thanks, that make sense!

Allan, A threaded nail was used on the two lower holes in my cowl, where there is no access to the back side. The nail is shown in the attached photos. I will try to reuse the nails, but if they don't work I will do what you did.