When to drill the top cowl to hinge holes?

[ArVeeNiner]

I'm in the process of fitting my cowl. It's a Sam James but I think this question applies to them all.

After trimming the rear of the top cowl all the instrutions and builder's accounts I've come across has you fitting the bottom cowl next. Only after the bottom cowl has been trimmed do you drill the top cowl to the top hinge.

I've been struggling to install the bottom cowl while trying to keep the top cowl from moving. It would seem to me that this would be a whole lot easier if I drill and Cleco the top cowl to the top hinge before fitting the bottom cowl. Then there is one less thing to keep from moving around while you adjust the bottom cowl.

Any thoughts? Will I shoot myself in the foot if I do this at this point?

[stan_markwell]

I have been using clear packing tape to secure the cowl to the fuse. Run some longway then a few layers paralell to the seam. It wont move...

[pierre smith]

If you'll get a couple of pieces of aluminum angle, say 3/4" wide and about 6" long, drill and cleco them to the cowl at about 10 and 2 o'clock and let them rest on the spinner back plate. It's an easy way to keep the cowl aligned with the spinner and the holes get filled later.

Regards,

[ken westlund]

we used duct tape to secure it to the fuse. try to get the front as close as you can. I don't know how the cowl you have is but the vans cowls are pretty bad. I had to redo the whole front to get it to satisfaction. i also redid the inlet for the carb because it was cocked to one side. good luck. lots of patience, fiberglass and filler. also instead of bonding the hinges with epoxy like it says in the directions I used lord systems acrylic adhesive. did some comparative tests and you have to destroy the hinges to get them off! where as the epoxy just pops off.
-K-

[ken westlund]

also when the time comes to fill the pinholes. dont dillute resin with acetone. you will degrade the properties of the resin. system 3 makes an epoxy bondo that works really well. and if you have some system 3 resin you can dillute the bondo with resin. works great!
-K-

[ArVeeNiner]

Originally Posted by pierre smith

If you'll get a couple of pieces of aluminum angle, say 3/4" wide and about 6" long, drill and cleco them to the cowl at about 10 and 2 o'clock and let them rest on the spinner back plate. It's an easy way to keep the cowl aligned with the spinner and the holes get filled later.

Regards,

Thanks for the replies.

Pierre, I've seen pictures of that very thing and it sure looks like it would work better than the popscickle sticks that I have hot glued on. You just look at them wrong and they pop off. Actually getting the guts up to drill into my cowl is going to be rough.

I'm new to fiberglass but I've watched a few YouTube videos on it and it looks very easy. How do you fill the holes afterwards? Would you just make a paste out of glass and epoxy?

Why not just drill for the hinge now?

By the way, I can't find anywhere on the Vans drawing what hole spacing and rivets to use. I imagine you match the spacing of the rivets on the top skin right? How far back on the hinge do you drill? Do you drill on the centerline of the hinge or maybe 1/4" from the loops on the hinge?

[rwarre]

I am also doing my cowl fitting on my 7A. I went ahead and drilled a couple of holes and clecoed the top cowl along with a quarter inch spacer in the front between the spinner and the cowl. I figure that if I have to change much, filling the holes shouldn't be a problem. I have the top and bottom fitted and they have lined up well. If you need a picture, let me know.

[ArVeeNiner]

Thanks.

What I ended up doing was put a roll of toilet paper under the cowl at the front of the engine. Between that and the popscicle sticks I have the front of the cowl drooping the correct amount. I then used packing tape at the rear of the top cowl. This all is holding pretty well while I work the bottom cowl.