Washcoat Of Shellac - How To ?

[leftyjay]

Hey all

I'm doing a DIY Carvin kit (ash body) and I did the following until today :

Sanding

Grain rising

Dye

I've just done a 1 pound washcoat of shellac, applied with a coton pad. I have the following questions :

How do I know if my coat of finish is thick enought ?

How long do I need to let it dry before applying my grain filler ?

I ask those questions because after doing that washcoat, I have the feeling like I was just putting alchool on the body. I mean, is it normal to still feel the wood even after putting this washcoat ? I know it's thin, but still.

Thanks !

[Drak]

You have jumped into the deep end of the pool my friend, I hope you can tread water.

Let me explain what you're trying to accomplish here, and how extremely tricky it is for someone who has not practiced on scrap

(which is highly recommended).

What you're trying to accomplish is a rather tricky, multi-step dye, fill, and finish procedure.

You DYE the wood first.

Then apply a very thin BARRIER COAT of finish (shellac in your case), designed to do several things all at once:

1. SEAL in the dye from the filler coming next.

2. PROTECT the dyed wood from the colorant in the filler.

3. Be THIN enough that the filler still can 'grab' into the pores and doesn't come back out when you wipe it off.

4. Be THICK enough that your filler doesn't color the wood.

This is Dancing with the Devil 101.

What will typically happen is that you won't get enough of the filler out of the pores, have a bunch left on the surface that you'll have to sand off, and when you go to sand your filler down, you'll sand right through the thin-assed shellac barrier coat right down into your dye, get a rub-through, and just be plain pissed off about the whole thing.

If you want this way to work, be prepared to get your filler job done damn near perfect right out of the gate.

One wrong slip, too much filler left on the wood, or not enough shellac to protect, or too much shellac and your filler can't 'grab', and you'll be screaming for the nearest lifeguard.

I would recommend trying the shallow end of the pool first, which means practicing a few times.

Grab some practice Ash, and practice this stuff on some scrap, because if there's anything I hate, it's stripping all my hard work off and starting all over again, which may very well be what you wind up doing unless you've practiced on some scrap, know what's coming, know what to expect, and know what to do when the unexpected happens, because it happened on scrap first, where it doesn't really matter.

[leftyjay]

You have jumped into the deep end of the pool my friend, I hope you can tread water.

Let me explain what you're trying to accomplish here, and how extremely tricky it is for someone who has not practiced on scrap

(which is highly recommended).

What you're trying to accomplish is a rather tricky, multi-step dye, fill, and finish procedure.

You DYE the wood first.

Then apply a very thin BARRIER COAT of finish (shellac in your case), designed to do several things all at once:

1. SEAL in the dye from the filler coming next.

2. PROTECT the dyed wood from the colorant in the filler.

3. Be THIN enough that the filler still can 'grab' into the pores and doesn't come back out when you wipe it off.

4. Be THICK enough that your filler doesn't color the wood.

This is Dancing with the Devil 101.

What will typically happen is that you won't get enough of the filler out of the pores, have a bunch left on the surface that you'll have to sand off, and when you go to sand your filler down, you'll sand right through the thin-assed shellac barrier coat right down into your dye, get a rub-through, and just be plain pissed off about the whole thing.

If you want this way to work, be prepared to get your filler job done damn near perfect right out of the gate.

One wrong slip, too much filler left on the wood, or not enough shellac to protect, or too much shellac and your filler can't 'grab', and you'll be screaming for the nearest lifeguard.

I would recommend trying the shallow end of the pool first, which means practicing a few times.

Grab some practice Ash, and practice this stuff on some scrap, because if there's anything I hate, it's stripping all my hard work off and starting all over again, which may very well be what you wind up doing unless you've practiced on some scrap, know what's coming, know what to expect, and know what to do when the unexpected happens, because it happened on scrap first, where it doesn't really matter.

It doesn't sound like it, but I did practice a lot and it went pretty good. The thing is I want this job to be perfect like you said. The thing is I don't remember how it felt (I did those test a few months back) to the touch once it is "perfectly done". Don't worry for me, I practiced a lot, read a lot, etc. But considering that is my main project, I wanted to make sure I had it the right way right off the bat.

PS : I don't really mind sanding a little too much since my dye is a little too dark !

[leftyjay]

oups, double post

No worries about double posting....just edit it like you did and hit the "Report" button so a moderator can prune as appropriate.

Edited June 19, 2010 by Prostheta

[Drak]

Well that's AWESOME then!

As long as you've done it a few trial rounds, you've got a shot at it.

OK, the shellac. You're going to have to go by 'feel', as a custom mixed cut of shellac can vary from person to person.

PS, did you de-wax the shellac first btw? It helps a lot to make sure there's no wax in the shellac.

If you think you're shellac is too thin, you can leave it out in the sun, some of the alcohol will evaporate and leave you with a somewhat thicker cut if you think you need it thicker.

I pretty much ran it by you above, you want it thick enough to protect your dye, and thin enough to allow your filler to 'grab' the pores.

That's the intent of the shellac.

By the sound of it, I'm thinking you need several more coats of shellac, but be warned, I'm not liking the cotton ball thing...as you apply more coats, you'll dissolve the previous coats and your rag may start sticking...be prepared for that scenario.

Start boning up on your filler application, that's where the rubber's gonna meet the road.

No matter what you do, do NOT sand that filler back off, under any circumstances, which means you really need to do a good job of rubbing it off on first application.

BTW, what kind of filler are you using, what's the dissolver, water or petroleum product?

You'll want some of that around to help you remove filler if you have to as opposed to sanding it off.

And if it's water, don't use a lot, your shellac coat is very thin, if you use too much water, it'll wick under your shellac and ruin the job.

As I said, very touch and go kind of operation.

[leftyjay]

Well that's AWESOME then!

As long as you've done it a few trial rounds, you've got a shot at it.

OK, the shellac. You're going to have to go by 'feel', as a custom mixed cut of shellac can vary from person to person.

PS, did you de-wax the shellac first btw? It helps a lot to make sure there's no wax in the shellac.

If you think you're shellac is too thin, you can leave it out in the sun, some of the alcohol will evaporate and leave you with a somewhat thicker cut if you think you need it thicker.

I pretty much ran it by you above, you want it thick enough to protect your dye, and thin enough to allow your filler to 'grab' the pores.

That's the intent of the shellac.

By the sound of it, I'm thinking you need several more coats of shellac, but be warned, I'm not liking the cotton ball thing...as you apply more coats, you'll dissolve the previous coats and your rag may start sticking...be prepared for that scenario.

Start boning up on your filler application, that's where the rubber's gonna meet the road.

No matter what you do, do NOT sand that filler back off, under any circumstances, which means you really need to do a good job of rubbing it off on first application.

BTW, what kind of filler are you using, what's the dissolver, water or petroleum product?

You'll want some of that around to help you remove filler if you have to as opposed to sanding it off.

And if it's water, don't use a lot, your shellac coat is very thin, if you use too much water, it'll wick under your shellac and ruin the job.

As I said, very touch and go kind of operation.

I use bartley's. That was the most suggested products. Compare to the water based, it worked like a charm. Thanks for the tips !

[leftyjay]

Here's the result so far :

Bottom 4th page

For info, check on the bottom of the 3rd page for what it does looked before the grain filling. The difference is not that big in person.

It went smoothly, but I have some questions :

The process seems to darken the color a little bit, even at a point it became "dull". I'm planning on doing a little sanding with P600. It should light things up a bit right ?

Furthermore, When I put my project on a 45 degree angle with the light, I can see a blotchy spot (it was there even before the grain filling). I think it's the shellac. I steel wool it a little bit with a result, but not perfect. Is there any other way to solve this ? Sanding I suppose ?

Edited June 22, 2010 by leftyjay