I am thinking on using a spray gun for the glosscoat like this dont have to loose time on sanding the brush marks.
The question is how many psi do i need?
I saw a mini compressor with 250psi.is that enough for the spray gun?
I’ll also want to use same compressor for painting the foam.
If the gloss coat is applied with the proper technique then you won't have any brush marks. The gloss coat is a self leveling resin with polymers in it that polish out nicely and need very little sanding with 400 or 500 grit depending on preference.
http://shop.fiberglasshawaii.com/resin/polyester_resin/surf/rpsf-surfboard_finishing_resin
We only suggest using a spray gun to spray on gel coats or other resins that have a similar viscosity as laminating, sanding or gel coat resin and it's a case by case kind of deal. Good luck!
A trick that I just used (one I learned deep in the archives of Sway) was to have something that vibrates near your board as the gloss coat hardens. I have a small aquatic air pump that I use as a vacuum pump. So, I have this pump turned on and it "jiggles" the stand ever so slightly. No brush strokes whatsoever. My best gloss job to date.
That right there is gold my friend… Thanks for the tip Dave. Though I could have used it a week ago and would have save me some sanding.
Cheers
If you're considering spraying a poly resin glosscoat, forget it. If you looking to spray some acrylic/enamel/urethane clear coat then you can set your regulator anywhere between 50-60 psi. Much depends on the viscosity, so if it's really thin you can use about 35 psi. The slower the dry time the more you'll need to take precautions on dust, etc.
Hi Colin-
All you need is a really nice 4" flat bristle brush. Brush your Gloss resin on the board, be sure to get the entire board covered with an even coat. Then "cross" brush the board one time and let it settle out. The resin will drip off the tape and the resin will self-level. As long as you have prepared the board correctly and are working in a clean environment it should come out great. Glossing is an art! Even the pros have a tough time with glosses.
Best of luck-
Brad
One thing Brad forgot to mention is that after you do your "cross" brush (rail to rail), to help even out the gloss, you'll need to do a finish pass. Brush the length of the board starting at the stringer working out to the rails. Also once at the rails take a few more passes end to end concentrating on the radius and lap area to make sure the whole rail is covered nice and even. If there is too much resin left on the rails the gloss can split as it flows out. Make sure the board is preped and cleaned well, get the resin out and on (you want it thin, smooth, and even), don't over brush the resin, then walk away and let it do it's thing. The quicker you get the resin on and brushed out the more time the gloss has to level before it kicks. Also make sure your area is free of drafts, if not you'll have splits and a wavey gloss.
I learned from a long time glosser back in the seventies to tap the board on the bottom while it is on the rack after you do your final pass with the brush it helps to level out the brush marks in a similar way as the vibration method
When I worked at Brewer, the glosser, Glen Ericson was a master glosser.
Used straight gloss resin.
His room had no air-hose, door had seals, so no drafts.
He blew off boards outside of his room. So no dust to kick up off the floor.
Pretty much used glossing methods discribed above.
No zits, brush strokes, and nearly no seam to sand.
Polishers dream.
You are right, glossing is an art form.
These days, people mix lam and gloss together, gloss out in the open,polishes look dull and blurry. Not many real glossing pros out there.
Flat bristle brush is key. Not a hot coat brush. It makes a huge difference.
No shirt=no dust=no zits.
Made for show quality polishes.
I learned a lot from him.
Still use many of the tricks he taught me.
Thanks Glen.
Brush rail to rail once (taking excess off the brush as you go), then lengthwise once. When done, I tilt the board from the tail a few inches and drop it back down on the rack and repeat for the nose (racks are padded). Close up the room and don't go in for a couple of hours and then pull the tape. I cut my gloss (sylmar) 5% styrene and 2% surface agent so it flows without slabing. Use a Purdy natural brush (4") dedicated for gloss only and keep it soaking when not used. Glossing is the only time I tape around the rails, use 3m 233 so there's no residue. Run a surform on the tape line if needed as soon as it's hard enough then do the other side.
glossed with rr epoxy today
called it a cowboy job
outside raining
under a tarp with the wind blowing
sanded after drying off with a towel
wiped and dusted with bare hands
degreased with epoxy dust and
repeatedly wiped off hands
on a towel aroun' my waist
did the bottom at noon
just before a rain squall
it cured in the rain atmosphere
then did the top rail after sunset
and that cured in the rain too
I brushed the fish eyes into submission
and walked away after about 1/2 hour
and by the grace of the spirits
it came out good enough
for a sophistcated calf roper
not a bullridercowbot job
or a bulldogger covered w/mud
…ambrose…
a sensei job costs more
I underbid the job at 100$
Whoops!!! Thanks Oahu for setting us straight on that. Definitely need to finish with very light strokes parallel to the stringer and finish off the rails. To many strokes and too much pressure will not be good. All good info in the last few posts.
so , Colin , it would appear [ from what people have typed above ] that brushing on the gloss coat will be the go … rather than spraying , eh ?
The big question being…
…how "DUST-FREE" IS your area, for gloss-coating the board, mate ?
let us know / please show us how it turns out , eh ?
cheers !
ben
It doesn't hurt to use fresh gloss resin, not some old shit that's been sitting in the shed for 3 years.
Shake the can each time you use it to mix the wax and other additives. Maybe try Kokua's recipe of additional shots of styrene + surfacing agent. Pour resin through a filter cone in to a clean dust-free bucket.
Don't hold your board down with one grubby, greasy, grimy hand while sanding with the other. I wear a rubber glove or hold a fresh piece of sandpaper with the hand that's doing the holding. I wear gloves when I'm taping the apron around the edge. Paw prints are a big source of gloss troubles.
Repeatedly drag pieces of masking tape stretched across the board until the tape comes out clean.
Some manufacturers list recommended proportions and temperature charts on the side of the can. Check the temperature and follow those recommendations. Or follow a chart like one of THESE.
Use 2 razor blades to pick out any loose brush hairs, stray animals, or other goobers. Peel off the apron just as the resin is starting to gel. If timed just right, it'll blend in a little rather than leave a hard edged seam.
If you're lucky, you might get a clean gloss coat that requires little to no fine tuning.
…very nice !
Polishing sucks. No need to do it unless it's going to some sort of show. That dull wax you see that rises to the surface makes the gloss coat harder and less scratch resistant. I never polish anymore unless someone begs for it. (And I can polish a board pretty nice in 30 minutes) Just rub out the tape line and ride the board.
ohhhh swaylockers THANKS A LOT
so no paint gun for the gloss… tooo bad now that my gfr's brother gave me a nice paint gun as a gift.