How do you finish wood?

[cracker39]

I know that this discussion abour thinning varnishes was a week ago, but I just got my email Woodworkers Journal issue and they had comments from various "experts" on the subjject. Here is the link.

http://www.woodworkersjournal.com/ezine/qanda.cfm

Their comments abouit how and why seem to vary as much as our opinions of a subject.

[madjack]

...that's because there is a kazillion ways to do most things...the one that works best for you is always the "proper" way to do something whether you agree with me or ya got it wrong again
madjack

[cracker39]

Rite agin Jack...Like I said, their opinions vary. I'm not sure I agree with any of them, and I still agree with you on the thinning. I found 10% for poly varnish works for me.

[asianflava]

What I ended up doing was brushing it on then spraying the final coat. I still didn't have parts or time to setup the gun so I used the spray can. I figured that I can get a thicker coat with the brush. Brush strokes were still visible after a few coats so I sprayed the last coat. I am happy with the results.

I will probably spray the inside but I have to get a respirator to do the inside of the tear. I'll pick one up when I get the gun parts.

Another question, do you clean the gun after every coat? or do you just leave it in the gun till you are done with that portion of the project?

[WoodSmith]

Clean the gun after every coat! Unless you can put the gun in an oxygen free environment, the finish in the various small places in the gun will dry/cure and stop up the gun in a big way.

You can clean the gun well after every coat and it will just take a couple minutes. OR you can clean the gun less frequently and spend a lot of time and have to use much more cuastic chemicals.

[doug hodder]

Asianflavia...I only clean the gun after I am done spraying that portion of the project...I will let it sit a short period of time while the paint or clear flashes off then shoot the next coat....Once I have the finish looking like I want...then I clean it....flush it out with lacquer thinner, the cheap stuff, make sure all the openings in the nozzle are clean from any debris... after the gun sits and you want to use it....that's when you'll find most of your crap in the gun from a poor cleaning job...It has now dried and the new material has loosened it up and is prone to plug the nozzle...and ruins a paint job....and it is a hassle to clean it then when it's all loaded up with catalized paint.....If it is a siphon feed gun...clean the opening vent in the pot....if HVLP gravity feed, clean the vent in the plastic lid....I only do a complete tear down on the gun after I've run a lot of paint through it and just can't seem to get it clean enough any more....good clean up after each job will make it a lot easier to use on the next job....that's what I do anyway....Doug

[cracker39]

Another question, do you clean the gun after every coat? or do you just leave it in the gun till you are done with that portion of the project?

I've done both. If it is fast drying between coats, I usually leave it in the gun. What you can do if you are using a bottom mounted cup, is unscrew it and put the siphon tube in some thinner or mineral spirits and spray some through the tip to clear it, then screw the cup back on. That would keep the tip from getting clogged. The cup on my guns also screw onto the gun, and has a thread that fits a standard quart jar. I can take the cup off and screw on a jar with thinner in it for clearing the tip (using siphon feed NOT PRESSURE with the glass jar on the gun). Then, I can put the paint cup back on for the next coat.

I haven't yet used my top feed gun I bought, so I'm not sure you can clear the tip with that type unless you empty the cup and put thinner in it.

When I clean my bottom cup guns when I am done painting, I clean out the cup with thinner (or water if it is water based paint), then put the thinner (or water) in the cup, replace it on the gun, and spray into a large cardboard box to clean out the gun some before disassembling it for final cleaning.

[cracker39]

After reading Doug's post, I want to clarify "disassembling". By that, I meant the tip portion so I can pour cleaner through it and blow it out with my compressor. I don't take out the needles etc. every time. Once in a while, I will completely tear them down for a real cleaning. I try not to wait for them to clog up before doing that.

[doug hodder]

Cracker...I always pull the tips and clean after every job....a handy item to have is a welders tip cleaner....I use it all the time to clean the nozzle...If you don't clean a nozzle well you will find out in a big hurry next time you want to spray....you'll get a funky pattern..curved or fat to skinny...if that's the case...you got a plugged nozzle...Doug

[cracker39]

The nozzle is part of what I clean every time it's used. By the needles, I meant the adjustments on the back. Those I don't remove every time. I rarely have problems with clogging because I do clean all parts that the paint contacts every time. I agree with you. If it isn't cleaned properly, it will clog up and is hard to get dry paint out of the works.

[asianflava]

When I worked in a paint shop, they would clean the gun after every job. The painters used a 2qt pressure pot so they had to clean the pot, hoses, and gun. They would spray solvent thru the gun from the pot then, disassembe the gun and clean everything. After the end of the day, they would soak the needles, nozzle, and whatever thay could fit into a can. They had tip cleaners cleaners that Doug mentioned but would use them very sparingly. I asked why and they told me that if you use them all the time, it will change the orfice size.

It just seemed like a lot of work to do which is why I asked.

[doug hodder]

You're right....only want to use them to poke the material through...don't use the abrasive portion of the cleaner heavily or it will screw up your tip...you also mention something critical "working in a paint shop" indicates that they are spraying a lot of material....I don't do that much.....doug

[Chris C]

Asian,

I agree with keeping the needle tip cleaners away from the gun..........only to be used if the tip becomes clogged. What I always do is to use the thinner compatable with the last finish. I fill the can about halfway full and shake vigorously while spraying. This cleans the can and suction tube. After I'm through, I COMPLETELY dismantle the gun, nozzles, everything and soak in the same thinner. Then I take a tooth brush and pipe cleaners to the contents until it's all clean. Then I reassemble the entire gun and, once again, put about a half can of thinner through the gun...................but don't run it completely dry. I put the gun up with thinner in it. When I go to use it again, it's clean and ready to go. I've never had a clogged gun and this method has worked for me for the past 45 years I've been spraying finishes.

[asianflava]

Add to that, they would shoot Mil-Spec paint, acid etch primers, epoxy primers, waterborne paint, you name it we shot it no matter how nasty.

One thing's for sure, I learned how tough epoxy primer is when we had to remove some of it. If I ever restore a car, it will get shot with epoxy primer.

[doug hodder]

Asianflavia....good point!!! there's lots of materials you can run through a gun....they all have their own properties....just clean it up well every time you use it and you'll save yourself a lot of time and ruined finishes in the future...whether you think it means tearing it down or just flushing it out....find out what works for you...and if in doubt....ask your paint supplier what he suggests on clean up....and just for grins...has anyone shot one with Zolatone? talk about a clean up mess!!!Doug