3D Printing Prepping and glueing PET 3D Fin can to fiberglass airframe

[TX-Redleg]

I purchased a 3D printed 54mm fin can from Additive Aerospace and I'm mounting it to a Madcow 54mm thin wall fiberglass airframe.

What is the best adhesive? Epoxy, Thick/Slo CA?

I believe AA uses PET and it feels slick, do I need to prep? IE sand with 220 grit and clean with alcohol or acetone?

Looking for recommendations, I plan to fly it to Mach 1.

Gordon

 

[rocketgeek101]

From their website:

To assemble, lightly sand the inside of the fincan and superglue onto your airframe. For supersonic flights, make a small epoxy fillet where the can meets the airframe.

 

[TX-Redleg]

Yes, I saw this on their website, but I'm used to washing fiberglass, then lightly sanding the area to be glued, wiping down with acetone to clean, then epoxying. I'm worried about the bond if I sand, but don't clean with something. I don't know which cleaners may damage PET, or if I should follow AA's guidance and glue with thick CA without cleaning the fin can. I will still sand and clean the fiberglass.

 

[rocketgeek101]

Yes, I saw this on their website, but I'm used to washing fiberglass, then lightly sanding the area to be glued, wiping down with acetone to clean, then epoxying. I'm worried about the bond if I sand, but don't clean with something. I don't know which cleaners may damage PET, or if I should follow AA's guidance and glue with thick CA without cleaning the fin can. I will still sand and clean the fiberglass.

You should be safe to rinse it with water or rubbing alcohol. I've done this without any issue for parts printed with PETG which I believe is quite similar to PET. Honestly not really needed though. I wouldn't recommend acetone though, as it will likely cause the outer layers of the fin can to soften.

 

[Landru]

You can use pretty much anything and cleanliness isn't super important other than no skin oils. Isopropyl is best for cleaning, and acetone works for very short contact times. The ridges in the filament make a very good mechanical bond when using epoxy as well.

I've gone past Mach with one only friction fitted with tape... Would not consider that good practice, though.

~Andrew

 

[JDcluster]

I used Proline 4500 on the Spool holder that need some stiffening by adding a G10 base plate. It was printed in PETG.