The consequences of not sanding between coats of poly

[Kansas City Fireslayer]

What John T said.  Seal coat then WB poly.  The smell isn’t that bad and definitely nothing compared to lacquer.  Seal coat sprays super easy as well.

Raising the grain with a WB will effect the overall sheen and look where the grain raises more in certain areas.

[blanning]

The only down-side to SealCoat is the odor and that will dissipate in a couple of hours.  With the warmer weather he can leave the windows open and get plenty of ventilation. 

The SealCoat is water-clear.  Other shellac finishes add amber to the finish. 

From my experience horizontal surfaces (like table tops) need a very durable finish.  Vertical surfaces are much more forgiving.  I would not leave pine bare however, as it will get dirty looking over time. 

The other advantage of SealCoat compared to other shellac finishes, is that it is already diluted to the "as applied" recommendation.  Other Shellac finishes require adding solvent to the finish to reach the correct dilution.  But if an amber tint is desired, shellac is a good way to do this.  Staining pine can be a chore because of the blotching.  Amber shellac will not blotch.

Thanks to everyone for the awesome advice.

Is one coat of SealCoat enough?  Or maybe a second coat of SealCoat instead of one SealCoat plus one poly?  The main goal is just to be able to wipe down the walls to keep them clean.  What's the advantage to mixing the two?

[fredhargis]

One application of Sealcoat is enough to prevent grain raising. The purpose of topcoating it is to provide durability. Shellac by itself isn't a very tough finish. The waterborne will adhere to it very well and allow you to wipe them down easily with no damage (as long as you avoid ammonia based cleaners).

[Bill Wilson]

I wholeheartedly agree with the shellac recommendations, but I'll add a little twist for your consideration.  If you want to use shellac only, without a topcoat, then I would suggest using regular shellac, with wax, like Zinnser Bulls Eye.  The wax will give a little softer, smoother feel to the finish than Seal Coat alone.  Either one can be sprayed easily, if you have a compressor and a cheap HVLP gun.

[Cooler]

If spraying, definitely wear a mask.  And open as many windows as possible.  Just two hours will do it for the smell to go away.

A funny story.

I built a sleeping crate for my Chesapeake Bay Retriever, and applied oil based poly inside and out for durability.  I let it cure for two weeks and then introduced the dog to the crate.  He refused to enter it even though he was insistent on sleeping in his old wire crate. 

After two days I bought a couple of rattle cans of SealCoat and sprayed the interior and exterior with one wet coat each.  That night the dog slept in the new crate.  The shellac fully sealed the odor of the poly which was still apparent to the dog after two weeks cure time. 

For a wall, I think SealCoat or shellac will be as durable as any latex paint.  Vertical surfaces do not get much wear except at the corners of walls.  If it does get damaged wiping with a rag damp with alcohol and it will often dissolve just enough to repair any damage.  Or you can add another coat without any prep if it is shellac over shellac.

I do agree that water based poly will adhere very well to the shellac and it is a tougher finish than shellac and you will breath easier while applying it.  You will have to weigh the advantages/disadvantages of each.

Here is almost everything you want to know about shellac.  I would note that while Sealcoat is generally recognized as a universal primer, I had issues with applying PPG's Breakthrough! over SealCoat.  It caused the finish to craze and it had the look of ancient paint that had cracks.  I tried this again allowing 72 hours for the shellac to cure and the same thing happened.  So the rule should be "Always test a finish over any primer or surface before proceeding with the job."

https://www.naturalhandyman.com/iip/infp...llac2.html

[blanning]

Thanks everyone for the responses.

[blanning]

I can't seem to find SealCoat at the box stores.  And Amazon seems to only carry quarts.  Based on 400sqft coverage per gallon, it looks like I need around 10 gallons.  My local lowes has one gallon (so their website claims).  And the other lowes in the area don't have any.  HD isn't any better.  Is there another store that carries this brand?  Or can someone recommend an alternate brand?

I see there there's an oil based version and an alcohol based version.  Am I right in assuming that I need to use the alcohol based version if I'm going to spray water based poly over it later?

thanks

[fredhargis]

Do you have a Menards nearby? They list a 5 gallon container, though it's ship to store. I'll be honest, I wasn't aware of an oil based version, but you want to real shellac based which would be alcohol.

[Bill Wilson]

I can't seem to find SealCoat at the box stores.  And Amazon seems to only carry quarts.  Based on 400sqft coverage per gallon, it looks like I need around 10 gallons.  My local lowes has one gallon (so their website claims).  And the other lowes in the area don't have any.  HD isn't any better.  Is there another store that carries this brand?  Or can someone recommend an alternate brand?

I see there there's an oil based version and an alcohol based version.  Am I right in assuming that I need to use the alcohol based version if I'm going to spray water based poly over it later?

thanks

I think True Value also carries Zinnser products, but I doubt they have 5 gallon pails in stock.  A few local ACE Hardware stores carry gallon cans.  Perhaps a local paint store could order it?

I've never seen an oil based version of Seal Coat.  If such a thing exists, it may not be a true shellac.  Zinnser Seal Coat is an alcohol based, de-waxed shellac.

[Rob Young]

I can't seem to find SealCoat at the box stores.  And Amazon seems to only carry quarts.  Based on 400sqft coverage per gallon, it looks like I need around 10 gallons.  My local lowes has one gallon (so their website claims).  And the other lowes in the area don't have any.  HD isn't any better.  Is there another store that carries this brand?  Or can someone recommend an alternate brand?

I see there there's an oil based version and an alcohol based version.  Am I right in assuming that I need to use the alcohol based version if I'm going to spray water based poly over it later?

thanks

Not from Amazon Warehouses but you can use them as the store-front : 

https://www.amazon.com/RUST-OLEUM-851-Un...=hi&sr=1-2


6 sources. Shipping varies.

For comparison, $39/gal delivered to store from Menards. And 5gal pail is $180 to store.
https://www.menards.com/main/interior-wo...061883.htm