Filtering finish

[dave_c]

HI All
I've been spraying stylewood and just noticed fine flecks of what looks like maybe dried lacquer!!!! I've seen a video of where in preparing the finish was filtered through a paper filter into the sprayguns pot. Is this the way to go with finishes to obtain the best possible result or just muddle though and sand them off between coats is the end result the same??

[router]

I have been using Stylewood for some time now and always pour the lacquer through a paper filter into the spraygun. It is sometimes quite amazing just how much gunk the filter will pick up from dust particles, old lacquer and so on. It is also important to make sure that the gun is clean and the surface which is going to be sprayed is free of dust. Sanding down between coats really is only to give the next coat a key for adhesion. If the job is sanded down heavily between coats it wil take more coats to get a build on the job. Highly recommend using a filter. Always ma ke sure you give the lacquer a good stir.
Good luck

Router

[woodPixel]

Spraying can be easy, or hard, depending on a hundred factors.

-- To eliminate troubles maintain scrupulously clean guns. Clean them for surgery!

-- Filter the material going into the gun with a disposable strainer (e.g. Supacheap have 5 packs for $3) and ELIMINATE moisture from your lines.

-- Employ a basic moisture filter at the tank. Use a series of copper pipes, about 5 metres worth, to create a series of "drops" to cool and condense the moisture from the tank. At the bottom of each drop, there is a basic tap to empty it of accumulated water (you will be horrified at the quantity). Use a decent filter and dryer at the end (such as this, but is exxe Amazon.com: DeVilbiss 130525 QC3 Air Filter and Dryer: Automotive ). Picture attached. It doesn't need to be super-dooper (for example, make it pretty, not ugly like the picture), but if you have 3 drops and taps you will be rewarded with very clean air.

No moisture literally eliminates 95% of your headaches.

If you filter the paint/stuff going into the gun you don't need to do more than that. You can get little insertable filters that sit below the pot before going into the gun, but I've never used them.

The other problem is "spitting" where slight accumulations build up on the nozzle air jets and harden, but then detach landing on your work (arghhh!!!!). Wipe the front of the gun occasionally with a paper towel. This happens to me all the time with oil house paints.

[Arron]

For spraying Wattyl Stylewood what I use is a combination of
1 those little plastic filters that sit in the gun, just below the pot. Get these from a panel eater supply place.
2 one of those very fine mesh metal filters bought from Daiso - which sits over the pot and can be taken off and rinsed in thinners. I think they are intended for Japanese tea ceremonies, so very fine mesh.

My only reason for using the in-gun filter is if I miss a bit of crusty stuff from the gun-cleaning it will stop it.

A comment you made interests me. You shouldn't be sanding between coats of Stylewood - in fact it kind of defeats the object of spraying lacquer. Spray sealer first, and sand it back hard. Sealer (like Wattyl Readiseal) is designed to be sanded so it sands like a dream. Once you have built up a velvet smooth base spray 2 or 3 coats of Stylewood. Stylewood is designed to resist abrasion and sanding is a type of abrasion so Stylewood is a pig to sand. You are basically just tearing the surface.Further there is no need to promote adhesion between coats by sanding as each coat partially melds into the coat below due to the action of the included thinners - which is what nc lacquers are all about. 2 or 3 coats of well filtered Stylewood, smooth straight off the gun and not frigged with. Leave till well hardened. Buff.

[dave_c]

Well thank you very much for your helpful comments.
i am new to the woodworking and spraying, sanding between coats is a light sand with 320- 400 grit to remove any fuzziness. i see people spraying without water traps, desiccant filters etc. to me the finish looks ok maybe to the trained eye something different! my compressor is a Fiac appears to have a water trap/reg/taps fitting but just recalculates it back into the tank probably not the place for it!!
Now I have a few mods to make the compressor system a little better and i'll check out the in pot filters and start filtering my finish.
One more question do you dilute the style wood with thinners and at what ratio?
Here's a bit of gratuitous self promotion at David Chadderton Furniture Designer and Maker - Home

Dave

[Arron]

I checked out your website. Very nice. Simple clean designs.

For the water traps - I use just the trap on the compressor and one of those $20 ones attached to the gun. I'm not saying that Routers solution is overkill, just that I don't need it for what I do so I haven't bothered with it.

For thinning, I typically use:
First coat Readiseal thinned 50/50
Second coat Readiseal thinned 60/40 (ie 60% product 40 thinner)
Third coat Stylewood 75/25
Fourth/fifth coat Stylewood 80/20

Download the product data sheets and have a read of them. The Wattyl ones are very good and can be relied upon. The manufacturers know their product and want you to get the best out of them (thence become a loyal customer). They target professional businesses who want good results but are very conscious of time and cost. It's far better information then what you will get here as unfortunately many users are self-taught and really strange ways of going about things predominate.