HVLP From Harbor Freight for Gelcoat

My automotive 1.4mm tip HVLP gun is missing some parts, and I remembered I bought this

to primer the garage walls when it was remodeled. It has a 0.7" tip which is around 1.8mm. I sprayed Kilz with it, think it’ll be good for gelcoat?
I found some guns with bigger tips online but need to spray this weekend. If it works out, I may just keep using it.

Youl spend more on chemical cleaning it than what it costs to buy a 15.00 gravity feed at hf. Bigger tip is better though I think hf has some suction guns for 20 bux

Wouldn’t I still have to clean the paint type gun? I’m not gonna be filling either cup type all the way to the top. Plus with this style, I can probably put a plastic bag in the cup and do something to keep the suction tube from sucking the bag up and creating blockage.
I tried cup liners on the paint style gun and didn’t get good flow.