can I print bondo?

is there a ready made disposable helical nozzle system that pre mixes polyester resin and hardener at the extrusion nozzle in the correct proportions.

I haven't seen one yet, but you could modify a paste extruder : [www.thingiverse.com]

Problem would be cure time, most resins and hardeners take time to cure and hold shape, most would puddle out after extrusion.

With bondo, it would be a bit hard to get the ratio right, but maybe something with a 1:1 mix ratio resin/epoxy would be easier.

I'm not sure why you'd want to print Bondo. It would not be a particularly good material choice for much of anything, IMO. It shrinks, cracks, and becomes brittle over time.

If I was going to explore that idea, I would use a paste extruder to extrude UV cured epoxy resin. Make sure the extruder is opaque and mount a powerful UV lamp in an opaque cabinet with the printer. With a sufficiently powerful lamp and a warm enough cabinet, you could probably get the cure time down to the 60 second level, or so. Normal cure times with UV resin tend to be around 3 minutes. There are resins that have enough body to be useful for all sorts of things.

Quote
Tom Brown
I'm not sure why you'd want to print Bondo. It would not be a particularly good material choice for much of anything, IMO. It shrinks, cracks, and becomes brittle over time.

If I was going to explore that idea, I would use a paste extruder to extrude UV cured epoxy resin. Make sure the extruder is opaque and mount a powerful UV lamp in an opaque cabinet with the printer. With a sufficiently powerful lamp and a warm enough cabinet, you could probably get the cure time down to the 60 second level, or so. Normal cure times with UV resin tend to be around 3 minutes. There are resins that have enough body to be useful for all sorts of things.

I used to be a prototype technician at my last job and the way we used to do it print it in plastic like you normally would. Spray it with some clear lacquer to seal it well make a soft silicone rubber mold and poor with any of the resins that are out there

Edited 1 time(s). Last edit at 05/27/2014 08:02PM by cnc dick.