Sanding sealer for acrylic paint

[Shambrick]

Hi Folks,

About to stat a new project - a STA-1M for my daughter.

This will be a pretty simple build, no real modifications and a simple paint job in acrylic rattle can (but good quality stuff).

I'm thinking it would pay to grain seal before sanding this time. Anyone have a view on what sanding sealer is compatible with acrylic paints? I'm thinking Feast Watson but not sure if there are compatibility issues (and their product info online is not that easy to navigate...)

Worst case I buy and test on sample wood, just thought it was worth asking the brains trust.

[fender3x]

I have been thinking about this too, and will be curious what folks think. At the moment I am leaning away from using sealer.

I have been experimenting with MTN 94 acrylic rattle can paint. It is billed as "the first true artist's spray paint." I don't know about that...but so far it is reasonably easy to use without sealer.

I have used it over unsealed, unvarnished pine. I filled the pores with drywall compound and sanded with 220 grit to get it flat. I needed 3-four coats sprayed in 10 to 15 min intervals to get it opaque. Thin coats with no sanding in between. Let it dry for 24 hours then sanded flat with 320 grit or 400 and the hit it with a grey scotch-brite sanding pad. I am a bit of a noob at this but to my eye it's amazingly flat, without working it that hard.

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[McCreed]

Ash will def require grain filling IME. There are numerous products and techniques to achieve this nowadays.
I've used Timber Mate with good results and it's easy to work with. Dries quickly, sets hard and sands well. (and it's water based, so easy clean up) There's also methods that include joint compound, super glue, epoxy etc.

As for sealer, I'm a big proponent of shellac (dewaxed). It goes on easily, dries quickly and is compatible with just about any topcoat. (certainly with any lacquers and enamels I've tried)
My mantra is becoming "when in doubt - shellac it". Whether you mix your own or buy it premixed, as long as it's dewaxed.

Shellac can also be used to grain fill using a slurry method with pumice, but I haven't tried that yet. (I have used the slurry method with Tru Oil, but that's a whole 'nother thread)

The process I would do is: grain fill > shellac > primer > base coat > clear coat.

Of course, some acrylic base coats will buff up just fine without the clear, but it depends on the product.

[Shambrick]

Thanks guys, I will check out both approaches

[fender3x]

Thanks guys, I will check out both approaches

Just remember that McCreed has a lot more experience than I do. I am still working on getting my first *good* finish ;-)

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[Shambrick]

Ash will def require grain filling IME. There are numerous products and techniques to achieve this nowadays.
I've used Timber Mate with good results and it's easy to work with. Dries quickly, sets hard and sands well. (and it's water based, so easy clean up) There's also methods that include joint compound, super glue, epoxy etc.

As for sealer, I'm a big proponent of shellac (dewaxed). It goes on easily, dries quickly and is compatible with just about any topcoat. (certainly with any lacquers and enamels I've tried)
My mantra is becoming "when in doubt - shellac it". Whether you mix your own or buy it premixed, as long as it's dewaxed.

Shellac can also be used to grain fill using a slurry method with pumice, but I haven't tried that yet. (I have used the slurry method with Tru Oil, but that's a whole 'nother thread)

The process I would do is: grain fill > shellac > primer > base coat > clear coat.

Of course, some acrylic base coats will buff up just fine without the clear, but it depends on the product.

Thanks McCreed,

Thinking about this a little more I will try your shellac approach. What is a good source of wax free shellac? Is it something I can get at 'Bunnies'?

[McCreed]

Hey Shambrick.
Yes/maybe. The big green shed does have shellac flakes. The only brand they seem to stock is Feast Watson but it doesn't specify whether it is waxed or dewaxed. You may have to have a look on the container or contact FW to verify.

I buy mine from a local furniture restorer supply shop. The FW is a bit dearer than I pay but not hugely.
Typically I mix mine to what is called a "1 pound cut". That means 1 lb. flake to 1 gallon solvent. It's basically a 1:1 ratio.
I mix in fairly small batches since I don't use tons of it in one go. It will keep dissolved for a reasonably long time in a well sealed container under "normal" conditions (ie: not a 40 degree metal shed)

In metric terms I would do 50 grams of flake to 50 mils of metho or 100g flake to 100ml metho etc. You get the picture.
100 mils should be heaps for a guitar body. (and probably a neck)
Also, it's worth mentioning buying good quality Methylated Spirits. I also get that from the shop I get the flake from. I won't use the Diggers stuff you get at Woolies or Bunnies. It has additives.

Lastly, store your unused flake in something as airtight as possible. Moisture is the enemy. If it gets old and "clumpy" you'll find it won't dissolve as quickly or thoroughly.

Feel free to ask anything else if needed. You can PM me also.

Cheers

[Shambrick]

Hey Shambrick.
Yes/maybe. The big green shed does have shellac flakes. The only brand they seem to stock is Feast Watson but it doesn't specify whether it is waxed or dewaxed. You may have to have a look on the container or contact FW to verify.

I buy mine from a local furniture restorer supply shop. The FW is a bit dearer than I pay but not hugely.
Typically I mix mine to what is called a "1 pound cut". That means 1 lb. flake to 1 gallon solvent. It's basically a 1:1 ratio.
I mix in fairly small batches since I don't use tons of it in one go. It will keep dissolved for a reasonably long time in a well sealed container under "normal" conditions (ie: not a 40 degree metal shed)

In metric terms I would do 50 grams of flake to 50 mils of metho or 100g flake to 100ml metho etc. You get the picture.
100 mils should be heaps for a guitar body. (and probably a neck)
Also, it's worth mentioning buying good quality Methylated Spirits. I also get that from the shop I get the flake from. I won't use the Diggers stuff you get at Woolies or Bunnies. It has additives.

Lastly, store your unused flake in something as airtight as possible. Moisture is the enemy. If it gets old and "clumpy" you'll find it won't dissolve as quickly or thoroughly.

Feel free to ask anything else if needed. You can PM me also.

Cheers

Thanks man,

I had the same thoughts on FW from Bunnings, could not see any inof on waxed / not waxed. For convenience sake I'll stop by tonight and if it is unwaxed, I'll grab some.

As for the metho - good tip (I too only ever drink quality Metho...)

[Bakersdozen]

FW flakes are apparently dewaxed

https://r.tapatalk.com/shareLink?url...6&share_type=t

[McCreed]

Very helpful link there Bakersdozen.

That thread got a little contentious amongst its contributors, but included some excellent info form Ubeaut. I didn't know about the "water content test" for metho. Very interesting and good to know.
Also a more clear and concise explanation on the difference of Industrial vs Supermarket methylated spirits than I provided previously.

Thanks,
Mick