grainfill and sanding sealer..the order of the universe
- Thread starter dmraco
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Cagey
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You may want to seal, then grain fill if only because the wood will soak up some of the fill material and you'll have to fill again as it shrinks back. But, in my experience you often need multiple applications of filler anyway, depending on the filler viscosity and how deep the grain is in the wood. So, it may not matter. It won't hurt things either way. If you're running a spray rig, you have to clean up the gun every time you use it, so weigh the cost of that aggravation vs. sand time on your first application of filler. First app is not a finish layer, so sanding is more of a lick and a promise. Your call. No right/wrong way.
Patrick from Davis
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I try to seal first with shellac because it is dissolved in alcohol and dries really fast, if it is war out. The grain filler takes longer so I'd rather have the wood not take up the solvents that take a while to dry/evaporate away. I know finish work is all about patience, but I do try to streamline it as much as I can.
Patrick
Patrick
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Wash coats work just as well as sealer, really. Lowers your inventory requirements as well. But, sealer is generally less expensive than finish (depending on where you buy it), and can be of a higher viscosity so it behaves as a sand/fill as well. When you're shooting a layer and sanding half of it off for levelling, you don't want to use finish product if you can help it. 4 or 5 coats of sanding sealer can get you level for less money and effort than 8 or 10 coats of lacquer. But, not all substrates need that much help. For instance, if you're shooting at Alder or Maple, it's pretty smooth already. Don't need to fill much, if at all. Swamp Ash or Mahogany, on the other hand, will fight you tooth, fang and claw to get smooth.
Tonar8352
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What really determines the order of a finishing schedule is the type of wood and what the final finish will be.
I think that is why you will find so many varying opinions on the products and their use. Also the products that are being used will have different manufactures recommendations. Since I only shoot nitrocellulose finishes on guitars I stick to the following schedules with occasional variation depending on the end game.
I generally use wash coats for two reasons. The first is I want to maintain the original look of the wood so it will not be impacted by the color of the filler. The second reason is that it also helps to soak down in the open grain and aid with the filler shrinking less. Wash coats have no filling impact but they do help seal the wood for the next step.
I use filler directly to the wood if I want to impact the color of the wood. Natural filler directly onto ash really helps the sweeping grain show through on see through finishes. If the ash is getting a pigmented color or unique shaded color then it gets a wash coat first then filler and then enough finish so that it is level sanded before any color is added. If I want to bring out the look of the grain with a dyed finish like blue I stain the wood first with dye then give it two wash coats of finish and then tint the filler to a dark color so the grain really pops.
The only time I ever use sanding sealer is if I want the finish to eventually fail or I'm replicating a vintage finish. Sanding sealer is not more viscous than clear finish but does have more solids and it builds faster, so it helps in getting the surface level faster. The problem is it is so soft from all the stearates they put in it to help it build that when the lacquer (which is much harder) starts to really cure and shrink the whole finish begins to check. Which is a good thing it you want to have a vintage style finish.
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