Builders' Forum Archives
Re: HVLP gun
Posted by J. Schott on Apr 5, 2007
I don't know the specifics on a hvlp other than it is designed to atomize the material using a large volume of air rather than pressure. The transfer rate of material is much higher than traditional guns, which is much more enviromentally friendly.
Here is my $.02 on spraying varnish. Most of your time is spent on prep. No matter which way you apply varnish, it will show every imperfection in your work. If you are not experienced with spraying with a hvlp gun, you may end up making more work for yourself. It is too easy to create runs and sags when spraying on vertical surfaces. I can lay down a coat of varnish on a 17 in 20 minutes using a foam roller and a foam brush to tip it with. When I'm done I throw them away and clean up is done. I could put a coat on 2 boats in the time it takes to set up and clean up spray equipment. There is also a safety issue with spraying. The varnish becomes atomized and therefore is much more flamable. There is a great deal of risk involved for the average builder that builds in their garage with many ignition sources.
Here is my routine for varnishing. I sand for the initial coat with 320, wash the boat and wipe down to remove any dust. I'll get my varnish ready to go and hit the hull with a tack rag right before appication. I use the high density foam rollers available at any big box home store. I roll then tip with a foam brush starting on the dry surface and across the section just applied. I will complete a whole panel to maintain the wet edge and move to the adjacent panel once done. Between coats I wet sand with 400 wash and repeat the process.
My secret weapon is penetrol in my varnish. I thin it with the maximum amount of the recomended thinner which is usually 10%. After that I add 2-4 oz of penetrol per quart. Follow this recipe and you will swear it looks sprayed. It's fun to watch it flow out into a mirror finish. Do not skimp on thinner, a cheap thinner will give you a "grainy" finish. I know this from experience. Here's proof of the $2 varnish application technique-Joey
In Response to: Re: HVLP gun by Jon B. on Apr 5, 2007
- Re: HVLP gun by Jon B. on Apr 6, 2007