My Nitro Refin Progress Thread

[Silence Kid]

I planned to post pics of a beautiful finished product, rather than create a thread for this - But I will drop any pretense of hubris; I don't have enough idea what I'm doing and will probably need help. Might as well show all the ugly along the way.

My reasons to refinish are: Protect against moisture and bring the guitar back to factory-original. I plan to follow this schedule inspired by the " 3x3 " method, and StewMac 'thin skin' nitro finishing schedule (if I comprehend their logic) :

1 - Prep, grain fill, dry, and sand
2 - 3 coats of clear (as sealer) during day one; 3 coats color (black) over the course of day two; and 3 final coats clear during day three
3 - Wait for cure, then wet sand/polish.

Initial points of concern I have:

• Is there any reason I should not sand to bare wood before I begin? Sounds like spraying nitro or grain filler over poly or even hardened TruOil would not -actually- cause issues? Still; am I better off removing entirely? Or if I test a bit and it sticks- any issue scuffing/cleaning what is there and laying finish on top?

• Any way to tell if the present finish is Stain only, TruOil, matte poly, or something different that may be reactive? Or explain to me why it does not matter, per above. Still NO clue what finish is on the guitar is at present. It's not grain-filled at all anyway; feel-able pores, but does the (visible below) slight sheen on the wood mean oil, finish, or just stained wood?

...Anyway. Sorry to get all weird over this, guitar has sentimental value and is a great sounding/playing axe so don't want to ruin it:

 

[justFred]

Re: My Nitro Refin Progress Thread

Email Reranch...they will get back to you quickly with the correct answer...trust them only...

 

[Ayrton]

Re: My Nitro Refin Progress Thread

Shellac is your friend. Think of it as a universal bonding agent.

Scuff up the body with 220. No reason to go all the way to bare wood unless a translucent finish. Seal the wood with sanding sealer or shellac. I would use shellac, but your choice. Grain fill and sand back, then sealer again (2-3 coats). Now is the time to get everything perfect. Fill any dings, repairs and so on, then primer. Once your primer is on, you will be able to better see any flaws. Deal with them now. Don’t stress about sanding thru the primer or sealer. If it happens, you can easily spray over.

Once you are happy with the primed body, start your color coats.

If you haven’t selected a color yet, I would suggest a lighter solid color. Much easier to get satisfactory results on the first try.

Ask any questions you like

 

[Silence Kid]

Re: My Nitro Refin Progress Thread

Thanks for the advice - emailed Bill at ReRanch whose quick reply was "scuff/lightly sand" whatever the present finish is. He also took a guess that there might have been an oil finish on the guitar.

I'm doing black because that was the original finish (bad luck, I know.) I was put in contact with someone with first-hand experience of G&L finishing in the 80s, and they indicate rather than sanding sealer, clear nitro was used- So that was my plan, rather than shellac or specific sanding sealer. Do I understand the body should be sealed before I use grain filler, either way? And are there any particular issues with using clear nitro as sealer?

I was also led to believe that a separate primer coat would not be necessary, given that I'm using black; can I forego primer since I'm spraying black? Or is the primary reason for the primer in this case to aid in identification of imperfections?

 

[ItsaBass]

Re: My Nitro Refin Progress Thread

It's generally better to seal before pore filling, and then seal again afterward. Sealing first eats up less of your grain filler and makes application smoother and easier (and will give what is generally considered to be "better" looking grain if using a translucent finish – not your case). But you can pore fill first if you want. I've done it both ways, and they both work fine with a solid color. Sealing first is just faster, less wasteful, and smoother/easier (i.e. all around more efficient).

Be sure you know the difference between grain filler and pore filler. Pore filler is the stuff you most likely want to use for a traditional filling job...but that ReRanch grain filler is fine if that's all you've got.

If it was my guitar, I would start with a blank slate, via stripper. But you can just sand what's there if you want. It won't hurt your results.

I would prime under black, myself, but you don't need to, as long as you have enough lacquer to give you a nice amount of color coverage. That one can likely won't be enough, even with a primer. I generally use two cans of ReRanch for a solid color, then at least two cans of clear on top of that. Another consideration of primer vs. no primer is how the guitar will look as it ages. If you want white to show through on chips and wear marks, then you must prime white. But if you want it to go straight from black to wood, you don't want to use primer.

You also don't need to clear coat over black, but again, you might want to anyhow. It depends on what you want. On a restoration of a guitar of that vintage, I probably would not clear coat, so that it would not have as much of a candy shell brand new look. Non-clear-coated black ages faster and looks a bit less candy-shell-like from the start (more in line with the age of the guitar IMO).

 

[Silence Kid]

Re: My Nitro Refin Progress Thread

Thanks again- If I wind up deciding I need another can of black for coverage, would there be a danger in leaving the guitar to sit and wait potentially a week till the new can arrived, or should I have the extra can at hand to spray the next coats ASAP? In other words, am I risking the coats not burning into each other if I don't spray in consecutive days?

 

[Ayrton]

Re: My Nitro Refin Progress Thread

Sanding sealer is basically quick drying clear lacquer, so it will work fine. The only con is the amount of clear you will have to use. I would suggest picking up a quart of premixed shellac from the big box store. You can apply it with a foam brush and will save you much time and money (cans of lacquer can add up)

You can use any lacquer based black as your primer, so while you are at the big box store, grab a can or two of lacquer black. Also by priming first you have a chance to make corrections. Take your time and don’t stress. There is nothing that can’t be fixed.

No concerns about time between coats as lacquer melts to lacquer

 

[ItsaBass]

Re: My Nitro Refin Progress Thread

You're welcome. You can put another can on whenever, as long as you clean the surface properly first (naphtha is good for that). In fact, I would recommend seeing how one can goes before buying anything else. You might like the ultra thin finish, and you might be able to sand and polish it without going through on the edges, if you are super careful.

As far as lacquer melting into previous coats, there is a lot of misunderstanding about that. Yes, a new coat of lacquer re-dissolves part of the previous layer. But the key word is "part." The entire previous layer does not re-dissolve and blend with the new layer, as some people think. A multi-layer lacquer finish is really a series of coats that are slightly blended at the top and bottom limits of the coats...not one giant coat that all melts together as one block of wet lacquer every time you apply a new layer.

 

[AlexR]

Re: My Nitro Refin Progress Thread

^But from an operational viewpoint, the sanding can indeed proceed as if the entire thing is one......which is the key.

If you are doing a solid colour (and black shows up the most imperfections) it really requires a flat surface for the opaque coats. So you need to either have it flat before you start the colour, or indeed use the first colour coats to show where the low spots are through sanding back (the way a misted black coat is used for showing up low spots in a top carve or neck). Once you have a uniform surface then a last coat before clear.

 

[ItsaBass]

Re: My Nitro Refin Progress Thread

As for sanding sealer vs. clear lacquer as your sealer coats, I highly recommend sanding sealer. It lays on nice and thick in a single coat, and it has a "slippery" additive that lubricates the dry sanding and prevents the paper from loading up with sanding dust. Thus it is excellent at leveling a surface quickly and easily, as well as filling in the very small wood grains, so that you don't have to use so much filler.

Deft lacquer sanding sealer is fine. It's available at many hardware stores (I get mine at O.S.H.), and it's only 5–7 bucks or so. One can is all you need to seal the bare wood, pore fill, and then seal the pore filler in with the rest of the can. Clear lacquer doesn't build nearly as quickly. I doesn't level or fill as well, or sand nearly as easily. You'll need way more coats and a lot more, and more difficult, sanding to get it to the point that sanding sealer gets it to in two or three coats, and 10 or 15 minutes of dry sanding.

 

[Jeff_H]

Re: My Nitro Refin Progress Thread

Everyone has given good advice. I generally go with what Ayrton recommends because his stuff always turns out perfect. I would work especially hard on the sealer and primer coat as suggested, to get the surface perfect. Those steps are going to guarantee that your finish looks great. Skip them and it might just look like a cheap black spray job, and you don't want that.

Good luck and keep adding pics as you go.

 

[justFred]

Re: My Nitro Refin Progress Thread

Think it is a beautiful guitar as is...black is really tricky...never myself been able to get a black paint job to come out...always little problems showing up...over and over...it just never worked out for me...
If this guitar is important to you...maybe leave it for now and start with doing a black paint job on a different guitar...
If you are going for it...naptha constantly before and during the actual painting process;
Stew Mac wait time before final sanding is too short...two months if you can...Also their sanding schedule needs several grits interspersed...final polishing with Finesse-it II as Reranch recommends really makes it fine...good luck...

 

[Ayrton]

Re: My Nitro Refin Progress Thread

because his stuff always turns out perfect.

Ha!

Not even close, but don't let that stop you.

 

[Silence Kid]

Re: My Nitro Refin Progress Thread

Think it is a beautiful guitar as is...black is really tricky...never myself been able to get a black paint job to come out...always little problems showing up...over and over...it just never worked out for me...
If this guitar is important to you...maybe leave it for now and start with doing a black paint job on a different guitar...
If you are going for it...naptha constantly before and during the actual painting process;
Stew Mac wait time before final sanding is too short...two months if you can...Also their sanding schedule needs several grits interspersed...final polishing with Finesse-it II as Reranch recommends really makes it fine...good luck...

I was tempted for a long time to leave it as-is, it could look a lot worse grain-wise: Two piece body (but not joined at the middle, only a bit of the bass bout shows the join) and I don't really mind the **** brown look, sort of 'period' anyway- But even if it's an oil finish (which I gather probably needs to be reapplied at some point if not now) I really don't like the feel and worry about my sweat. It's 100 degrees and I soak a guitar if I try to play it.

Speaking of it being 100 degrees- I plan on doing my spraying outside, and taking the guitar in my garage for drying. I gather the temperature will cause the finish to be quicker to harden- a good thing? Any reason I should wait till December when we're back in the 70s or so?

 

[Lake Placid Blues]

Re: My Nitro Refin Progress Thread

I was tempted for a long time to leave it as-is, it could look a lot worse grain-wise: Two piece body (but not joined at the middle, only a bit of the bass bout shows the join) and I don't really mind the **** brown look, sort of 'period' anyway- But even if it's an oil finish (which I gather probably needs to be reapplied at some point if not now) I really don't like the feel and worry about my sweat. It's 100 degrees and I soak a guitar if I try to play it.

Speaking of it being 100 degrees- I plan on doing my spraying outside, and taking the guitar in my garage for drying. I gather the temperature will cause the finish to be quicker to harden- a good thing? Any reason I should wait till December when we're back in the 70s or so?

Yes, spraying in high temps causes all kinds of problems. I like to spray early in the morning when it's still cool. You want the temps to be in the 60s or at most the 70s which will probably be well above dew point, and also you want the humidity to be relatively low. When spraying during high temps you run the risk of getting it too dry by the time it hits the target. This results in orange peel. If you move closer to get a wetter application then you run the risks of run and drips. The main problem with spraying in too high of temperature is that the outside of the coat cures too fast, before the gasses can get out from below, causing porosity. High humidity can cause a haze in the coat because of water vapor trapped in the coat.

 

[Lake Placid Blues]

Re: My Nitro Refin Progress Thread

To further expand on what I have learned about spray can nitro. No more than three coats a day and let the last coat dry to the touch before the next pass. Let it cure over night before the next three.

The darker the color the more it will show imperfections from below, so with black you need to get the surface as perfect as you can before applying the color coats. If you get an acceptable color coat with one or two passes then don't add more. The more you do, the more can go wrong, and you want to keep it thin overall.

Your going to want to wet sand the clear coat starting with 600 to get a professional grade shiny finish, so you want 6 passes of clear- so you don't sand through. Three the first day and let it cure over night. Then three the next day and let it cure over night before you start wet sanding. Use McGuire's ultimate compound for the final polish. Wait two months before applying a synthetic automotive wax like Ice. The reason I apply and automotive wax is because it will have effective UV protection in it to slow down the yellowing of nitro.

 

[GuitarDoc]

Re: My Nitro Refin Progress Thread

Email Reranch...they will get back to you quickly with the correct answer...trust them only...

No. There are plenty of capable quality guitar repair/refinishers on this forum.

 

[GuitarDoc]

Re: My Nitro Refin Progress Thread

For the seal coat, lacquer sanding sealer is better than clear lacquer...it has higher solids content and builds better than clear. But if your guitar currently has an oil finish, shellac id your best bet. Shellac acts like a bonding agent between the previous finish and the new finish.

Don't get paranoid, lacquer is very forgiving and very easy to work with. Make a mistake, get runs, too thick in spots, orange peel finish...don't worry just sand it smooth and add more lacquer.

ItsaBass and Ayrton have given solid advice.

 

[Silence Kid]

Re: My Nitro Refin Progress Thread

Thanks again- I'm now thinking about whether I need to wait for winter to do this or find a cool place to spray. That's my excuse for the delay anyway.

As for Shellac, Ayrton appears to have used (or linked to) Zinsser. Is there any brand I should avoid? Feel like I'm going to go that route.

One more question: I seem to notice people not masking the neck pocket when they do this. My neck pocket is very tight already- should I mask?

 

[Lake Placid Blues]

Re: My Nitro Refin Progress Thread

I have used Zinsser shellac for this exact purpose before with no problems. Shellac is an organic substance so brand shouldn't matter.

You don't need to wait until winter, just shoot early in the morning.