Hi there, Dick.

I've varnished a couple of kayaks with a cheap HVLP unit from Harbor Freight. As I had no prior experience with spraying (aside from auto paint cans), I encountered a rather steep learning curve. So, if this is the only boat you'll be doing, it may be a tossup as to whether it's worth it.

First, the 'pros':

The final gloss and smooth surface of the sprayed varnish requires no buffing. Once you get the hang of it so that you don't get runs, sanding between coats is minimized; I sand only lightly about every 2nd or 3rd coat to remove specks and insects. You can recoat sooner, sometime after the prior coat has tacked up.

Now, the 'cons':

It's more work to set up: You need a segregated room with some sort of air filtration system; otherwise you end up varnishing your entire shop with the overspray.

You need a personal respiratory protection device like a good face mask cartridge respirator to protect you not only from the varnish overspray but, more importantly, the nasty solvents you'll need to thin the varnish to spraying consistancy. To protect my own clothing as well as minimize my own shedding, I wear one of those silly, hot, hooded Tyvek suits.

Finding the proper thinning ratios and spray gun settings takes time and experience. Off to one side in my booth, I have large sections of cardboard and scrap plywood that I use to make my initial 'shots' to establish varnish volume and fan width. I haven't tried any fan width less than an inch or so, and that just for the coaming ares; mostly I use a pretty wide fan pattern.

When I used Z-Spar's 2015 Flagship varnish and Pettit's 12121 Old Salem spraying thinner (both have the same parent company), a tech advice guy said to thin as much as 30% while the varnish can label says only 20%. Thinner coats, of course, mean more coats are needed to achieve the same final thickness. I normally apply 8 to the deck and 6 to the hull. This also means you have to buy about 50% more varnish than someone brushing the same boat with the same varnish.

Not having a rotating armature device to rotate the kayak, I have to do the entire hull first with all coats, then flip the boat to do the deck after masking off the hull to prevent overspray onto it while I spray the deck.

As with brushed-on varnish, surface preparation will determine the final result, only more so. ALL FLAWS WILL BE REVEALED.

So, that's the short of it. I don't mean to put you off, but just to give you a heads up that it probably won't save you any net time or effort. Check the archives for postings by Ian Johnston (unsure after this long about the last name, but his first is definately Ian) on this. He helped me with some advice about starting out.

The reward is that you'll have a very nice finish when you're done.

One other possible caveat: While I have made it work for me, I'm not at all sure that my $50 spray gun is really a true HVLP unit. It looks very much like the catalog photos of older, higher pressure units sold by other suppliers; all the purported 'pro' model HVLP units are quite pricey. Also, I've had some, few, instances of Harbor Freight products not being labeled properly. I recently bought a device sold as a pressure regulator, but was really only an in-line valve with a pressure gauge tapped in.

Now, this may be a reflection of my own ignorance or inexperience, or it may be real, I can't tell. In any event, however, I have been able to make it work to get a good result.

Pete Roszyk,
in Snohomish, WA