Would someone please explain the reason(s) for applying shellac then a coat of polyurethane. 

I recently showed a pic of something I called a drink stand, made out of some cherry. I applied a coat o garnet shellac, then a coat of varnish (sorry, not urethane varnish). Anyway, the purpose of the garnet shellac was to add a little color to the mismatched coloring of the cherry scraps I used. To my eyes, garnet shellac on cherry has a nice evening effect on the color, and is just good looking. Otherwise, I'll use shellac to insure adhesion. Urethane finishes are known for not sticking well to some things, sometimes not even themselves. A coat of dewaxed shellac (which sticks to almost everything, and the reverse) will ensure that the urethane (or polyurethane) finish will adhere to it. At least that the reason I (sometimes) do it. So shellac will seal in, for example, wood with suspected silicone contamination. It will also give a good barrier between BLO and the urethane varnish.

I agree with what @Fred W. Hargis Jr said.  For me I use shellac as a primer coat. Dries faster, easy to sand for next coat. Saves alot of time. 

Also shellac is THE universal sealer. It can be used between or under any other finish. So if you are not sure what the old finish is seal with shellac and continue

Thanks, guys. My curiosity has been satisfied. 

1 hour ago, Gene Howe said:

Thanks, guys. My curiosity has been satisfied. 

Big shop like yours, 55gal drum.

 

1 hour ago, Gunny said:

Big shop like yours, 55gal drum.

 

????

7 minutes ago, Gene Howe said:

????

 

Well you don't wanna run out once you up ramp up production.

 

You've been on hiatus for 18 months, time to get to work.  

With a little practice small items such as the recent eggs can be finished while on the lathe by burnishing a coat of shellac on them.  Apply, burnish until dry.  Sometimes use heavy paper and sometimes use a small piece of heavy cloth for application and burnish.

13 hours ago, Gunny said:

 

Well you don't wanna run out once you up ramp up production.

 

You've been on hiatus for 18 months, time to get to work.  

Agreed!

20 hours ago, Gunny said:

 

Well you don't wanna run out once you up ramp up production.

 

You've been on hiatus for 18 months, time to get to work.  

And all this time I thought he had been working ON the shop

Just now, Gerald said:

And all this time I thought he had been working ON the shop

 

Well all around it anyway. Planting flowers and such OUTSIDE isn't getting work done inside.

2 hours ago, Gunny said:

 

Well all around it anyway. Planting flowers and such OUTSIDE isn't getting work done inside.

No! But it does build up goodwill with SWMBO!

 

Today, she gave me my freedom. I made sawdust. 

3 hours ago, Gene Howe said:

Today, she gave me my freedom. I made sawdust. 

Sorry, I'm really late to this, but agree with comments by Fred, Gunny, and Gerald.  I think their initial comments covered it well.

On 4/21/2022 at 1:01 AM, Gene Howe said:

Today, she gave me my freedom. I made sawdust. 

amazing lol