Spray gun nozzle size

[orval]

Hi,

I have some Polyvine Wax Finish Varnish that I used on a stripped wooden door. It took a while to apply and I have a load of other doors to do so I thought about spraying.

Polyvine's literature states that their decorator's varnish can be sprayed but no mention of spraying for wax finish varnish. So I contacted them and asked. They said: "All of our products are suitable for spray guns, some models of spray guns may need the products to be slightly diluted."

So then I contacted the technical helpline of an online spray gun retailer. They said they need to see the data-sheet so that they can find out the required nozzle size. The data-sheets for the two products in question do not mention nozzle size. So again I asked Polyvine and had this reply:

"We cannot state a nozzle size as all spray guns are different. If you find the varnish is not coming out of the gun effectively then the product can be watered down to up to 10%."

Which just seems a bit odd to me.

So I either need to come up with a nozzle size to get advice from the online retailer, or hopefully someone here knows what will work and where to buy. I'm after a budget/DIY model -- it may be a while before I need to use it again.

Any advice would be much appreciated!

 

[RobinBHM]

Nozzle sizes for conventional HVLP gravity cup spray guns generally range from 1.2 to 2.5mm

Furniture lacquer is likely to spray ok with a nozzle of 1.6mm. BUT....all depends on type of material and viscosity. Perhaps somebody else on here that sprays might be able to advise what tip size they use.

Most lacquers will need thinning. Yes you could spray straight from the can by using a large nozzle size but all you would achieve is extreme orange peel. The key is to thin the paint until it is possible to fully atomize the material. Water based materials are a bit more tricky as they will tend to break down if thinning more than 10% and rapidly become too watery. Solvent based materials can be thinned a lot more.

One thing to remember -whilst you might save time spraying, you will be surprised how much material you will require! Especially if you need to do quite a few spray outs to practice.

 

[orval]

Thanks for the info RobinBHM.

I'm not sure if this helps but the "Relative density" according to the data-sheet is "Approx. 1.03 at 20 C (ISO 8962)". I don't know what that means, my guess was "3% more viscous than water" but that's cannot be the case -- it's kind of gloopy.