Hello Guys,
Just did a search on this site on spaying varnish using a HVLP gun and couldn’t find a lot about it. You guys that spray, do you have a favorite varnish? I have read the labels on the spar varnishes that are in the local big box stores and paint shops but haven’t found any with clear spraying instructions. I have found several which say that they are not for use on surfaces that will be submerged in water. What’s your opinion?
Thanks Guys
Mack
spraying with a HVLP sysetem
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Patricks Dad
- Posts: 1476
- Joined: Wed Oct 13, 2004 1:11 pm
- Location: Warrenville, Illinois
This topic is of interest to me as well. I see that it collected no responses so I'm responding to it to bump it back up to the top of the list.
Epifanes (Glen's favorit varnish) also sells a thinner specifically for spraying so it apparently is readily sprayable. I have a friend who has offered to spray my canoe but I didn't want him to drive all the way over to my house multiple times to spray the hull multiple times so I elected to brush it (at least the inside - I'm still contemplating asking him to come spray the outside).
There are several posts on this forum from guys who have sprayed finished on canoes or kayaks. I was reading the archives just this evening about someone who sprayed a very (very) hard 2 part compound on his canoe with great success. There is also a thread on LPU on the West Coast Paddler site. Interesting to read and the thought of spraying on several coats without sanding in between keeps me awake at night (or is it my sore back from sanding?)...
Edited: To answer your question about varnish and use below the waterline. That is a warning that relates to boats that will be in the water constatnly. If you (as do most) intend to take your boat out of the water after use any of the marine varnishes will be fine.
Epifanes (Glen's favorit varnish) also sells a thinner specifically for spraying so it apparently is readily sprayable. I have a friend who has offered to spray my canoe but I didn't want him to drive all the way over to my house multiple times to spray the hull multiple times so I elected to brush it (at least the inside - I'm still contemplating asking him to come spray the outside).
There are several posts on this forum from guys who have sprayed finished on canoes or kayaks. I was reading the archives just this evening about someone who sprayed a very (very) hard 2 part compound on his canoe with great success. There is also a thread on LPU on the West Coast Paddler site. Interesting to read and the thought of spraying on several coats without sanding in between keeps me awake at night (or is it my sore back from sanding?)...
Edited: To answer your question about varnish and use below the waterline. That is a warning that relates to boats that will be in the water constatnly. If you (as do most) intend to take your boat out of the water after use any of the marine varnishes will be fine.
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John Michne
- Posts: 116
- Joined: Sun May 09, 2004 7:36 am
- Location: Clifton Park, NY
- Contact:
Let me tell you about my HVLP experience. I was at a woodworking show, complete with lots of vendors. One vendor was demonstrating an HVLP spray system. She had an easel set up with a big piece of paper on it, and was showing how one could spray product with virtually no over spray. She had the gun adjusted for just a small pattern, then sprayed it right out in the open, in a crowded hall, and it worked flawlessly. I had to have it. $1000 later, I had a four stage turbine system, and set about to spray Interlux Brightside one part polyurethane on my newly stripped guide boat.
Since I only wanted the outside of the boat painted, I masked off the stems and gunwales with newspaper and blue masking tape. That took a couple of hours. Then I fired up the system, adjusted the product flow as per directions (starting with zero flow and aiming at a large piece of cardboard, gradually open the flow valve to get the desired pattern without runs). Then I sprayed the hull. The first coat was done in a mater of minutes. I let it dry tacky for 15 or 20 minutes, and shot it again. Then I shot a final third coat.
The demonstrator back at the show said to clean the gun, shake some solvent in the gun and pour it off, followed by shooting some more clean solvent until it ran clear. Right. Even though the solvent sprayed clear, the paint color was still visible inside the gun. It took another hour or more to disassemble the gun, wipe everything off, and reassemble it.
Then the biggest surprise – the hull was not smooth, but covered with dust nibs. The way the system works, the four stage turbine is blowing continuously, even when the trigger on the gun is not being pulled. All that high volume air stirred up shop dust that was there since the dinosaurs roamed, and settled on my nice shiny beautiful finish.
HVLP has the potential to do a fantastic job, but setup and cleanup time negates any time saved over brushing. The dust can only be prevented if the spraying is done in an enclosure specifically designed to be dust free.
For sale – four stage Apollo model 1000 HVLP system, complete with turbine, all hoses, gun, and instructions. Used once. Contact me if interested.
John
Since I only wanted the outside of the boat painted, I masked off the stems and gunwales with newspaper and blue masking tape. That took a couple of hours. Then I fired up the system, adjusted the product flow as per directions (starting with zero flow and aiming at a large piece of cardboard, gradually open the flow valve to get the desired pattern without runs). Then I sprayed the hull. The first coat was done in a mater of minutes. I let it dry tacky for 15 or 20 minutes, and shot it again. Then I shot a final third coat.
The demonstrator back at the show said to clean the gun, shake some solvent in the gun and pour it off, followed by shooting some more clean solvent until it ran clear. Right. Even though the solvent sprayed clear, the paint color was still visible inside the gun. It took another hour or more to disassemble the gun, wipe everything off, and reassemble it.
Then the biggest surprise – the hull was not smooth, but covered with dust nibs. The way the system works, the four stage turbine is blowing continuously, even when the trigger on the gun is not being pulled. All that high volume air stirred up shop dust that was there since the dinosaurs roamed, and settled on my nice shiny beautiful finish.
HVLP has the potential to do a fantastic job, but setup and cleanup time negates any time saved over brushing. The dust can only be prevented if the spraying is done in an enclosure specifically designed to be dust free.
For sale – four stage Apollo model 1000 HVLP system, complete with turbine, all hoses, gun, and instructions. Used once. Contact me if interested.
John
Here's my take on HVLP spraying. I was one of the guys discussing it on West Coast Paddlers. I also have some info on it on my blog: spraying wr-lpu
I can echo some of John's comments in that there is a lot of air movement and the setup and cleanup takes longer than the spraying. As well, spraying wr-lpu is likely more tricky than solvent based urethanes so keep that in mind when reading my blog. I didn't mind the cleanup process because I just washed everything with water. The wr-lpu dries pretty quick on the needle so you need to be careful to not let the sprayer sit after your finsihed spraying. It's best to rinse it out with water right away. I would dump out the excess wr-lpu and then fill the sprayer with water and run it for a minute. I didn't have any problems with dust and I don't think my shop was particularly dust free. Perhaps I had dust problems and I just don't see them in the finish? Certainly there weren't any protrustions of dust in the finish (ie nothing sitting on the surface that could be felt).
With my limited experience and knowledge, the following seems logical to me.
1. if you're using solvent based urethane/varnish then brushing is easier and much cheaper
2. if you're doing large surfaces, spraying would be a huge time saver
3. if you're spraying solvent based finishes, you should get an hvlp system
4. I believe some states (CA) have legislated the use of hvlp for environmental reasons - you have to use this type of spraying
5. despite the amount of chemicals that I use to build a boat (fiberglass manufacturing, epoxy, solvent for epoxy cleanup), I still would like to try to minimize my impact by using water based finishes. I think I will continue to use wr-lpu but I can't help think that me and my little canoe and a bit of urethane isn't all that bad either. If I try urethane I guess I'll try to spray it just for kicks.
BTW, I bought the hvlp used and share it with a friend to help mitigate costs. As well, if spraying wr-lpu was easy I would be touting it and renting it out to local builders for a very small fee.
I can echo some of John's comments in that there is a lot of air movement and the setup and cleanup takes longer than the spraying. As well, spraying wr-lpu is likely more tricky than solvent based urethanes so keep that in mind when reading my blog. I didn't mind the cleanup process because I just washed everything with water. The wr-lpu dries pretty quick on the needle so you need to be careful to not let the sprayer sit after your finsihed spraying. It's best to rinse it out with water right away. I would dump out the excess wr-lpu and then fill the sprayer with water and run it for a minute. I didn't have any problems with dust and I don't think my shop was particularly dust free. Perhaps I had dust problems and I just don't see them in the finish? Certainly there weren't any protrustions of dust in the finish (ie nothing sitting on the surface that could be felt).
With my limited experience and knowledge, the following seems logical to me.
1. if you're using solvent based urethane/varnish then brushing is easier and much cheaper
2. if you're doing large surfaces, spraying would be a huge time saver
3. if you're spraying solvent based finishes, you should get an hvlp system
4. I believe some states (CA) have legislated the use of hvlp for environmental reasons - you have to use this type of spraying
5. despite the amount of chemicals that I use to build a boat (fiberglass manufacturing, epoxy, solvent for epoxy cleanup), I still would like to try to minimize my impact by using water based finishes. I think I will continue to use wr-lpu but I can't help think that me and my little canoe and a bit of urethane isn't all that bad either. If I try urethane I guess I'll try to spray it just for kicks.
BTW, I bought the hvlp used and share it with a friend to help mitigate costs. As well, if spraying wr-lpu was easy I would be touting it and renting it out to local builders for a very small fee.
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WestCoastPaddler
- Posts: 29
- Joined: Tue May 31, 2005 4:33 pm
- Location: Vancouver, BC
- Contact:
I sprayed my last boat with System 3's WR-LPU and had no real problems at all and was quite happily impressed with the final outcome.
The first coats were a bit on the rough side, but subsequent coats resulted in a fairly smooth finish. The finish wasn't perfect so I ended up wet sanding to 1200 and then followed with a buffing. The final outcome was a very impressive finish. Total time to do the LPU finish from the final sanding on the boat -- about 12 hours.
Beginning to spray the WR-LPU:
After the fourth pass with the buffer, things started getting very shiny:
The deck completed:
The finished boat (complete with salt water marks on the deck):
More photos of the LPU application are starting here:
http://www.westcoastpaddler.com/buildin ... 12&pos=206
Would I spray again? Yes -- the finished result was quite nice. But, I'm going to apply the LPU on the Bear Mountain Enterprise that I'm currently building with a roller and brush -- not because I think it's easier, but because I know that I can get excellent results applying the LPU this way and since I'm documenting the build, it will show what's possible without going to the expense and learning of using a spray system. I built a double kayak a few years ago and brushed (and tipped off) the LPU and it worked fine.
Dan
http://www.westcoastpaddler.com
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The first coats were a bit on the rough side, but subsequent coats resulted in a fairly smooth finish. The finish wasn't perfect so I ended up wet sanding to 1200 and then followed with a buffing. The final outcome was a very impressive finish. Total time to do the LPU finish from the final sanding on the boat -- about 12 hours.
Beginning to spray the WR-LPU:
After the fourth pass with the buffer, things started getting very shiny:
The deck completed:
The finished boat (complete with salt water marks on the deck):
More photos of the LPU application are starting here:
http://www.westcoastpaddler.com/buildin ... 12&pos=206
Would I spray again? Yes -- the finished result was quite nice. But, I'm going to apply the LPU on the Bear Mountain Enterprise that I'm currently building with a roller and brush -- not because I think it's easier, but because I know that I can get excellent results applying the LPU this way and since I'm documenting the build, it will show what's possible without going to the expense and learning of using a spray system. I built a double kayak a few years ago and brushed (and tipped off) the LPU and it worked fine.
Dan
http://www.westcoastpaddler.com
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Dan
My Enterprise build is documented at http://www.westcoastpaddler.com/buildin ... p?album=15
My daughter's Magic build is here: http://www.westcoastpaddler.com/buildin ... p?album=17
My Enterprise build is documented at http://www.westcoastpaddler.com/buildin ... p?album=15
My daughter's Magic build is here: http://www.westcoastpaddler.com/buildin ... p?album=17