Exhaust

[Harry Babb]

Can I use the same Epoxy resin and Biaxial glass on exhaust pipes that I used on the other glass work on my boat???

I need to take the 6" fiberglass tube, cut it and form a 90 and a 45 degree elbow.

Harry

[lobsta1]

I believe that Patrick has stated in the past not to use epoxy for this application due to a lower thermal point than regular polyester. If I am incorrect I'll be corrected in the AM.
Al

[Bruce]

Lobsta is correct. Polyester resin on exhaust.

Depending on what I'm building, I may tack sections with some chop strand.

Once I'm sure the angles, or straight is correct I don't use anything heavier than ounce and a half. This allows me to conform the mat to angles and lay flat. Severe angles sometimes requires the use of chopped strand.

I use multiple layers over joints getting wider on each layer as I go out.

If you wait till dry between layers, sand and wipe with acetone before applying next layer. Make sure you sand and wipe the tube also.

[CaptPatrick]

Harry,

Forming a 90º in an exhaust must be done through four 22 1/2º transitions... A dead 90º, (two 45º), is too abrupt of a flow change.

I will polyester glass up any custom fitting that I need, but if a standard elbow or fitting is available from the companies making exhaust tubing is available, I usually by their fitting.

The only place I use epoxy in an exhaust system is in bedding the internal flange of the exhaust tube to the transom.

Glassing the interior joint of the exhaust tube is a real bitch. Rather than glassing I make a flange from Coosa board, dry fit it, and tack it to the tube. Remove the assembly, polyester glass it up in the shop, and reinstall it using thickened epoxy between the flange & transom. Exterior side of the joint is polyester glassed to the hull.

Br,

Patrick

[Harry Babb]

Thanks guys

I'm off and running..........

Harry