Is a spray and chop system necessary?

if you have a composites business, is it viable to only layup by hand, or would it be necessary to purchase a chop and spray system? im asking because i am considering buying one.

A lot depends on the parts you are building. There are many companies that don’t use a chopper gun (aka spray-up).

Chopper guns are typically used on larger parts like swimming pools and power boat hulls etc.

They are messy and unpleasant to work with, I have not had the displeasure of being around one for over 20 years now. Run away!

you could always but just a chopping gun while still brushing on the resin system. easier way to build thickness than going through the whole hassle of buying and using an entire chop and spray system.

If your last experience was 20 years ago, you should get aquainted with the new stuff. Magnum-Venus-Plastec (MVP) has equipment that is light years ahead of what was available back then. No atomization of the spray - now it is more properly referred to as a flow coat. The chop is directed into the flow path and onto the part. Yes, there is some overspray that hits the floor but it’s nothing like it used to be.

A good operator can chop small parts just as well as large parts. In fact, a chopper gun is most advantageous with small and medium sized parts. Cutting rolled goods (mat) for a bunch of small parts takes forever compared to running chop. Wetting is almost automatic and consolidation rolling takes much less time as well.

this is the one im looking at https://www.youtube.com/watch?v=y7rh1de8CGs. but perhaps i will stick to hand layups for now since im only creating auto body panels.

i was looking into getting this system that is pretty affordable and suitable for my smaller parts. https://www.youtube.com/watch?v=y7rh1de8CGs. But i think i will stick to hand layups for now.
roger, do you think that system is what you are describing as the newer technology for chop and spraying?

I didn’t know those guys were still in business. 8-10 years ago, I looked at their equipment and it looked like it was well built. However, I stuck with MVP because I already had some of their equipment and an excellent relationship with the feild tech rep.

I don’t know how their equipment works as far as the spray pattern goes. The MVP stuff uses “impingment” to create the spray pattern. Impingment, as MVP uses the term, is basically two solid streams of fluid colliding with one another. This collision creates a fan pattern that, in a perfect world, hits the mold surface as a sheet of resin rather than an atomized spray. In reality, the pattern is more like a fan of small droplets (still not atomized). Much less overspray and better control over where the material lands.

I’d ask them for a demo.

I am sure they are far better these days, I still despise polyester shops as it’s just messy and unpleasant.

Today I use mostly epoxy layups, pre pregs, infusion although I do some small polyester repairs and make my own moulds using poly too. Keep it to a minimum.