What glue? What lapping material? I'm an experienced builder but have not joined an ABS cowl in thirty years and have forgotten how. If I recall, we used some kind of solvent then but that is the extent of my memory.

I've some 1/64 plywood scraps, would that be suitable for the lapping material?

Thanks
arlyn

What I've done...

Align it and tack it with CA then fiberglass the seams with thinned finishing resin. Then renforce the soft spots with more fiberglass. Sand, paint, enjoy.

I usually use scraps of ABS for lapping and CA for gluing

Use strips of tape to secure and align the cowl.

Then TACK glue the cowl in several places with thin ca. When the ca has dried, remove the tape.

Use strips of 2 oz fiberglass cloth about 1 1/2" - 2' wide. Place the strip over the seam on the inside of the cowl. Use a piece of scrap music wire about 1/8" in diameter to hold the fiberglass in place and use THIN ca to secure it to the cowl. Don't forget to add a strip around the back of the cowl as support/reenforcement for the attaching screws.

After everything has dried, use spot putty (red stuff in a tube in the auto section of Wal-Mart) to fill the outside of the seams.

Sand the putty smooth, prime and paint.

No, not the red stuff! The blue stuff! Super Fil. The red stuff is way to heavy.

I've been using 2 or 4 oz glass for joining then pvc pipe glue. A quick spray of 3m77 or 3m45 holds the joining glass in place while gluing. Dont use a big glob of pvc glue, it might melt the abs if its real thin. Thick pieces have never given me any trouble.
Edwin

I like PVC cement better than CA. It's not as brittle, and to me it makes a better bond. You can either span the seem with ABS scraps or use fiberglass cloth. Both work great.

Thanks to all for the input...

I had to assemble a three piece cowl for my Herr Pitts Special kit. Used pieces of the flashing to back the seams on the cowl half. CA seemed to slightly melt the plastic giving the seams a very solid bond. Used microballons to fill in the seams.

somegeek

It is nice to get a report of how answers helped. I followed the advice to use fiberglass tape and CA and it went great. I used 3/4 inch wide glass and thin Ca after cleaning with acetone and taping the outside. I first did the aft borders and then the joints and had absolutely no problems holding the glass down and gluing in steps.

I found the red body putty but not a blue and the red worked great. It sands smooth enough for primer very easily. It is heavy but very little is left on so on larger planes it is not much issue.

Thanks again for all the input.

arlyn

The best way to handle ABS cowl is to replace it with a fiberglass one.