Aqua Coat Pore Filler - Luthier Tips du Jour Mailbag
In this episode, Robbie O’Brien answers a question about pore fillers. He demonstrates how to use Aqua Coat brand pore filler on a guitar.
Video Transcription
[on-screen text reads: Luthier Tips du Jour Mailbag]
Mailbag question: Can you recommend another pore fill product that is better than epoxy?
Robert O'Brien: Today's Tips du Jour Mailbag question comes to us from California. "Dear Robert, I've been using epoxy for pore fill, but I'm not completely satisfied with it. I get good results, but don't like the amount of sanding I have to do, the dry time, or the toxicity of the product. Can you recommend another pore fill product? Alan, in California."
Water-based transparent pore filler
Alan, I've used just about every pore fill product available, including epoxy. And like you said, you have the overnight dry time, you have the toxicity of the product, and yeah, you got a lot of sanding to do, too. However, I do like the results I get with epoxy, so if I'm going to use another product, I have to get similar results. Recently I started using a product that I got from LMI. It's called Aqua Coat. It's a water-based transparent pore filler, and I think it's going to solve the problems you mentioned in your email here.
How I use it
So let me show you how I use it. All right, Alan, here's my product, and what I've done is sanded my guitar up to 220 grit, and I've removed all of the dust from the pores. I don't want anything impeding the product from getting into the pores and filling the pores. Now to apply it, you could use a little rubber squeegee like this. You could use a plastic Bondo type spreader. Or to make it really easy, you could use just a paper towel. Just wipe it on, wipe it off. I've also made this super high-tech little spatula here out of a cutout from a spruce top, and I can just reach inside the pot of goo here and just wipe it on like that. Now just come in, so, and just work it into the grain [Robert works the product into the guitar back using small circular motions].
One of the cool things about the product is that it applies very easily. And just wipe it in there and you can keep it really clean, so there's very little sanding required with this product. Now it is water-based, so it's going to dry very quickly. So work in small little areas. A little bit goes a long way. Most of your transparent pore fillers that are out on the market are not really transparent, but this one truly is transparent. So that's another bonus. I recommend that you get it on there and wipe off your excess if you don't like to sand. And you indicated to me in your email you don't like to sand, so I would recommend getting it back off of there as soon as possible. You need the excess. It is also a water-based product, so if you haven't raised the grain, it probably will raise the grain just a little bit and you can sand that out later.
Notice how I'm working across the grain in circles, trying to work it into the pores. And then don't forget to wipe off the excess so you don't have a lot of sanding to do. And there you have it. And that took, what? About 30 seconds to do the complete back there. So it goes very quickly. Now I'm going to go ahead and do the rest of the guitar. By the time I get done, this is probably dry, ready to lightly scuff sand it because raised the grain. Then I'll apply a second coat.
Lightly sand, blow the dust out of the pores, and reapply
So by the time I got pore fill on the entire guitar, the back is already dry. Since it raised the grain slightly and to help the next coat adhere, I'm going to go ahead and just use some 320 grit paper on a pad here and just lightly scuff it. And since you can wipe this thing almost completely clean when you're applying it, there's really not much sanding to do at all.
So just a light scuffing there, that puts the grain back down. And then I would clean the dust out of the pores, because there's still some pores in there. So I'd probably take out my air hose, blow all that out, and then apply a second coat. So I sanded the entire guitar just real lightly with some 320 grit. I took it over to my air and then blew all of the dust out of the pores. And now I'm going to apply a second coat. The second coat goes on just like the first coat. Make sure you keep it clean so you don't have a lot of sanding to do. And you can really wipe it, almost burnish it in there and wipe it extremely clean. And what I'm going to do is apply this coat, lightly sand it again, remove the dust, and then do it a third coat. And that's all it takes. And I think you'll be happy with the three applications. If you're not, rinse and repeat until you are. And that's all there is to it.
So Alan, as you can see, the product sands easily, so check. It has a quick dry time, so check in that department as well. And it's low in toxicity. So all three of the things you mentioned are a plus with this product. So Alan, the only thing you haven't mentioned is compatibility with other finishing products. And I always recommend that you do sample boards or test pieces with any finishing products that you're going to use to make sure it's compatible with your top coats or your seal coats or anything that you're going to introduce into that finishing product mix. And I think that this product is going to suit your needs. Perhaps it's the product for you, so give it a try.
[on-screen text reads: More Luthier Tips and online courses available at www.obrienguitars.com. Private and small group guitar building and finishing instruction available.]
