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Forum topic by Joel_B posted 01-03-2018 03:58 PM 345 views 0 times favorited 3 replies Add to Favorites Watch
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Joel_B

347 posts in 1500 days


01-03-2018 03:58 PM

I borrowed a friend’s cheap Rockler HVLP sprayer.
I will be using it to spray WB Poly on pieces of the nightstand I am building.
This will be my first time using a spray gun.

First I am try to to decide wether to do it in my garage and setup some plastic sheet walls for overspray, or do it in the backyard which would require no extra protection.

Should I hang the pieces vertically or lay them down horizontally, especially the large side pieces. I have some plastic painters points I could lay them down on so I could spray one side and immediately flip it over to do the other side.

Any tips for getting the edges?

Can I leave the poly in the gun while I wait for each coat to dry, or do I need to clean it immediately after each coat? I plan to do 3 coats over one day. Temperature will be in 60’s but I could bring the pieces inside the house to dry faster.

I will be practicing on some scrap or cardboard.

Thanks for any advise.

-- Joel, Encinitas, CA


3 replies so far

View pintodeluxe's profile

pintodeluxe

5741 posts in 2932 days


#1 posted 01-03-2018 04:18 PM

Spray indoors where you can control the temperature, humidity, as well as keep bugs and leaves out. Use fans for ventilation. Often you can heat a work space for a few hours prior to spraying, then run fans and partially open a garage door for fresh air.

Yes you need to clean out the gun after each coat. I clean my gravity feed HVLP conversion gun after each coat when spraying lacquer or shellac. I don’t like poly. Sometimes you can get away with spraying without cleaning, but it’s a gamble. Every third time you do it, it won’t spray right. That’s why I clean my guns after every coat (it takes 2 minutes to disassemble the gun and soak it in re-usable thinner).

I don’t need to cover anything in my shop to spray lacquer or shellac. You may with poly (oil based poly for sure yes).

Lay the components flat on a temporary work surface. A couple pieces of 1/2” plywood on sawhorses work great. Vertical pieces have the potential to run or sag, but the finish will lay down best if the parts are horizontal. Lay a part flat down on your work surface and spray the back side (no edges yet). Then put out some painters pyramids (or wood blocks with drywall screws sticking up) and flip the piece right side up. Then hit the edges, and finish with the field.

Painters pyramids can dent large or heavy workpieces. It’s a problem even with dense hardwoods. That’s why I never put project pieces on pyramids to spray the back side. Set directly on your temporary work surface for spraying the back side.

Spray sample boards to get the feel for the gun before you spray your project.

Good luck!

-- Willie, Washington "If You Choose Not To Decide, You Still Have Made a Choice" - Rush

View msinc's profile

msinc

497 posts in 623 days


#2 posted 01-03-2018 04:31 PM

If this is your first go at spraying you definitely want the items to be horizontal. Shoot them with a light “tack” coat first and give it a minute {or two} to tack up good then go back and finish. Don’t try to spray too much at a time or too much overall. Practice on wood pieces not cardboard. Cardboard will start to absorb the spray and fool you into believing that you have it down pat when in fact it is hard to get runs on cardboard because it will just drink up the finish.
Not sure why you are doing three coats…when I finish wood stuff I always apply the “build” coats with a good brush and then when that is good and dry {and also thick enough} I spray it one time and I am done. There are all kinds of ways to finish wood, this is just what works for me. Every time I tried to spray bare wood I ended up applying way more coats than I wanted to, to the point it was just not worth doing. Not sure what you are gaining by trying finish something with all spray????
The other thing I do is apply the finish coat to one side and clean out the gun, then the next day when it is good and dry i flip it and do that side…even with Japan drier I couldn’t get more than one or two coats a day. Suggest you don’t leave product in the gun, What is in the pot will be okay, but what is down around the needle wont and it’s not your gun. Best of luck. You might need it, but don’t worry….you gotta learn sometime!!!

View Carloz's profile

Carloz

1147 posts in 710 days


#3 posted 01-03-2018 04:55 PM

Definitely horizontally ( even if spraying not for the first time ) whenever possible. Also I do not know if there is any benefits in the light “tack spray”. When spraying WB with too little spray you get a dull lackluster finish. Someone said if you are not getting occasional runs here and there you are spraying too little. I would agree with that.
Normally I spray outside. 60F is on the little cold side but should still work. You can bring the pieces inside after spraying. Saves a lot of over spray mess in the shop.
Yes you can leave the poly in the sprayer between coats. ( 1-2 hours) just tape the nozzle with masking tape so it will not dry out.

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