HVLP Spray, or do it the old way?

[Julie Moriarty]

I had a long post, complete with pics, I thought I posted but since it isn't here, I guess I didn't hit "Reply".

Anyway, I again wanted to thank everyone here. You've given me some great ideas and hope that maybe owing a sprayer is the one thing keeping me from finishing the things I build. They are stacking up like planes over a snow covered airport. In 2005 I made an entertainment center and the staining and finishing was such a chore (it was 24" deep) I've hated finishing things ever since.

Even though I knew this obvious step was looming in my future, I decided to take on re-facing the kitchen cabinets. They are SOOOOO ugly! Now I've painted (no pun intended) myself into a corner.

I "recalimed" some floor space in the basement that had turned into a workshop overflow area. Now the spray booth is feasible. I have block magnets from fire alarm jobs I've done over the years and I can use those to hold plastic sheeting to the ceiling grid. I could make a decent size spray booth and when I'm done, pull off the magnets and toss the plastic.

I built some dust pickup fans for the shop air that have (1) 1" cheap filter and (1) 5" HEPA MERV 13 filter. I'd take out the HEPA filter and replace it with five cheap filters. That should be enough to pick up the overspray. Now I'm trying to imagine actually enjoying finishing my work. What a concept!

[Gary Hodgin]

Sounds great.

[John TenEyck]

Well, the concept is good Julie, but I would not recirculate that air back into my shop, filtered or not. Those filters will not absorb VOC's and you don't want them sticking around in your shop/house, you want to exhaust that stuff outdoors. And if you ever plan to spray shellac, you'll get a good hangover if you don't exhaust it. You will be much better served by figuring out how to vent your temp. spray booth outdoors. My early experiments with home built filters proved that they just load up and then you lose your CFM. Forget the filters and exhaust directly outdoors. Your CFM won't drop off and you won't have any residual VOC's (or particulates) remaining in your shop/house. If you are worried about the temp. dropping off in your shop, don't. I've sprayed for nearly an hour straight, exhausting 1200 cfm out the window, and the temperature in my 65 deg heated shop never goes down more than 1 deg. I turn off the furnace while spraying just so that it doesn't have to fight for combustion air. There's just too much mass in the room for the make-up air to cause much of a temperature drop in that short a time.

You're getting there. Keep at it and you'll soon have some beautiful, safely sprayed projects.

John

[Julie Moriarty]

Well, the concept is good Julie, but I would not recirculate that air back into my shop, filtered or not.

The guy at Woodcraft said the fan/filter combo would work for waterborne products. He said he blows it back into his shop. As for oil based, he would not recommend this. I'm an electrician and I've done installations in explosion proofed rooms. A simple box fan with all the filters in the world won't pass the test.

The whole idea of going waterborne is reducing the smell in the house. I've sprayed small pieces with lacquer and the house stunk for days. If I tried to do that with this project, we'd have to move or build an explosion proof booth. Neither are planned.

IF, as I have read here and elsewhere, most of the overspray dries up before it hits the ground, then venting outside shouldn't be necessary. I could, by running 8" flex to a window nearby. The more I think about it, the better I like it. And it wouldn't break the bank or take forever to set up.

[John TenEyck]

The guy at Woodcraft said the fan/filter combo would work for waterborne products. He said he blows it back into his shop. As for oil based, he would not recommend this. I'm an electrician and I've done installations in explosion proofed rooms. A simple box fan with all the filters in the world won't pass the test.

The whole idea of going waterborne is reducing the smell in the house. I've sprayed small pieces with lacquer and the house stunk for days. If I tried to do that with this project, we'd have to move or build an explosion proof booth. Neither are planned.

IF, as I have read here and elsewhere, most of the overspray dries up before it hits the ground, then venting outside shouldn't be necessary. I could, by running 8" flex to a window nearby. The more I think about it, the better I like it. And it wouldn't break the bank or take forever to set up.

Julie, I hope your next to the last sentence means you like the idea of venting out the window. Yes, filters will catch much of the overspray, but they won't catch any of the VOC's. Plus filters plug up and become less effective over time, and as they do more overspray goes uncaptured and some of it is so fine that it floats in the air for hours and settles on everything eventually. I know this from experience. The guy you talked to at Woodcraft is happily ignorant, and likely to get even dumber/sicker, if he does much spraying that way. Just because you can't smell the VOC's doesn't mean they aren't there; in fact, they are there unless you vent them outside. The beauty of WB products is you can use any fan that does the job since you don't have to worry about explosive solvents. You can even use shellac, IMO, which is flammable, but only when you get to a concentration of at least 11%, IIRC, and that will never happen if you blow it outside. You'd probably pass out if you recirculated it into your shop before you got to 11% concentration, but I would not recommend trying that out. In the end, how much work is it to vent it outside for the peace of mind of knowing you are not negatively impacting your health and the health of others? You have a lot of doors to do, plus other projects. It's not like we're discussing a one off where you plan to use a quart of finish. You are going to be spraying multiple gallons of finish - that's a lot of VOC's.

John

[Scott Holmes]

Julie when you spray cabinets, etc... If at all possible leave the backs off until the spraying is finished, much easier to spray that way.

[Darius Ferlas]

Julie, you don't have to spend $500+ for a decent HVLP spray system. A $300 Earlex will do the job just fine and woodwerks.com sells it with two tips (2mm and 1.5mm). The Wood Whisperer has a good video review of the Earlex 5000. The newer model is 5500.

I used a HF HVLP system I bought for the same as I do for a gallon of decent WB finish, and the results were respectable.

[Jim Becker]

Julie, I'm late to the party, but I'm very satisfied with using a relatively inexpensive HPLV conversion gun with my 60 gallong compressor. I only spray shellac and water borne products. I can never recommend spraying things like lacquer in a home shop environment unless there is a full, professional spray booth setup with the required filtration and exhaust setup. Spraying oil based products isn't necessarily great due to the very slow dry times and very, very sticky overspray.

My gun retails for about $130...actually, I have two of them. A 1 quart version that I use 95% of the time and a 2 quart remote pot version for the rare, but deadly "big job". Both are Wagners.

[daniel lane]

Attachment 256469

John, nice cabinet, nice finish! However, now you've inspired me to install a wine cabinet in the master.


daniel

[Julie Moriarty]

After boring to death anyone who was polite enough to hear me carry on endlessly about what to do, I decided on buying a HVLP sprayer. I went with the Fuji Super 3 and bought the 6' flex attachment and #2 and #3 tips. I'm using General Finishes waterborne dyes and their Enduro-Var satin top coat. The GF website said #2 tip for the dyes and #3 tip for Enduro-Var. What do I know? If it doesn't work, I'll blame them.

Today I took some 6" flex duct that has been sitting in the garage forever and a 24x24 return insert made for a drop ceiling, also been sitting in the garage forever. I ran the flex from the return vent to the nearest basement window. I also bought a 25x25 cheapo filter I'll use to cover the return vent. With some plastic sheeting, magnets and a few other Rube Goldberg items I have lying around the house, I'll fashion a quasi-spray booth. If I'm not too embarrassed, I may even post pics.

In a very Zen way, I'm feeling one with woodworking for the first time since I built that cinder block/2x12 shelf way back when I was in college.

[John TenEyck]

Good deal Julie. You went the expensive route on the sprayer compared to a cheap conversion gun, but I'm sure you'll like it. Now, just leave out the filter. If you are blowing the air outside all the filter will do is plug up and lower your flow. The fan won't care about dried finish particles going through it.

John

[Julie Moriarty]

Good deal Julie. You went the expensive route on the sprayer compared to a cheap conversion gun, but I'm sure you'll like it. Now, just leave out the filter. If you are blowing the air outside all the filter will do is plug up and lower your flow. The fan won't care about dried finish particles going through it.

John

Thanks John! I was wondering how much overspray would actually make it through the exhaust duct. The only time I've ever seen a HVLP sprayer in action was in a video. Kinda hard to tell that way. Now I won't have to figure out how to hang the filter on the ceiling.