Wood Dents Appearing While Patinting

[bockscar]

Hello folks. I've been working on my latest project, which is basically the restoration of a Jazzmaster copy. A friend of mine wanted it pained a Greenish-Yellow and, the guitar was pretty worn out anyway so I happily accepted the project.

The problem I'm running into is that, I've sprayed about 1 full can (Spray Can) of paint on the guitar, but now I am seeing massive ridges, dents, and otherwise scratches raise. I'm not exactly sure where the heck these came from.. There was a layer of grainfiller (or so I thought) on the body after I took the original paint off. I put about 5 coats of grey primer and I didn't notice these imperfections then.

I still have another can of the paint that I can use. Should I use some kind of filler on the imperfections now and paint over them, or should I just start over? I'm a little confused as to what the heck happened but, I'm more interested in making the guitar look good. In all honesty, the marks could probably be clear coated over and look O.K., but I am nit picky.

[Rockhorst]

I've never painted a guitar, but I'm pretty sure pictures would be helpful

[Tim37]

Pics

[bockscar]

Ok, I took some pictures and here they are!

This is on the front of the guitar, right below the tremolo cavity.

And here is the back of the guitar, right below the tremolo cavity

And this is also the back of the guitar, by the stomach contour.

As you can see, the paint still requires a bit of sanding. Could I actually apply some polish to the paint after I've sanded it? What are my options?

[LightninMike]

what those pics are revealing is that it was not well sanded .... never assume that the sanding sealer that was on there before would still be there after removing paint.... treat it like it's a brand new project and go from there...

[bockscar]

Interesting, my mistake. That's what I get for cutting corners

What is the best way to remedy this, or at least make them less noticeable?

[LightninMike]

well, you will need to sand it down to remove the scrapes.... then hit it with a sealer to double check that the scratches are gone...then start the priming/final color from there

[xadioriderx]

sanding sealer isnt foolproof. i sanded well, did 2 coats of sealer, and a few cans of paint, still have grain showing in the texture. i think the plastic finish is all a hoax

[westhemann]

i think the plastic finish is all a hoax

I(and a lot of others) use medium CA glue as a sealer..and then i follow it with a decent finish..I use catalytic varnish

[xadioriderx]

wouldnt that take a lot of glue?

[westhemann]

Not so much.There is no magic involved.You just fill the pores with something that won't sink in over time and then you use a nice,hard curing finish over the top.You can play with sanding sealers and spray cans or you can research,experiment,and find what works for you.

Finishing takes experience to learn,and you won't get it by giving up and settling for grain showing through.Your grain is showing because your sealer and your spray cans cure too slowly and the finish just sinks in.You can just keep on filling until it cures enough to stop sinking,or you can use a faster curing and more stable product.

You don't even need a separate "sealer" if your finish product is high quality.Mine cures hard enough to sand in 15 minutes,and reaches full cure in 24 hours,because it cures chemically.

I use CA to seal because it allows me to create a flat surface more cheaply than just starting to apply expensive clear directly.The guitar pictured has one thin coat of medium CA topped with several thick coats of Sherwinn Williams Sher-wood Water White Catalytic Varnish.

You can reach the goal with spray cans and sanding sealer,but personally I like to finish a guitar and string it up in 3 days.

[xadioriderx]

wow, very interesting. i guess ill have to make some adjustments to my finishing process for the next one! thanks!

[demonx]

When I'm building, once I get to sanding stage, I have foam cut out to sit the cuitar on, stops it from getting scratched and dinted up.

As others have said, it's simply that you've skimmed over your sanding process rather than going into fine detail.

As far as sealing - I use a cheap 2k clear (if its a transparent guitar) spray several coats, wait a week, sand it back and repeat till all the grain is sealed.

Another thing, if you're getting these kinds of scratches in your wood, you probably want to read up on your paint process as you'll get them in your clear too.

Good luck!

[westhemann]

wow, very interesting. i guess ill have to make some adjustments to my finishing process for the next one! thanks!

Thank you for listening.So often people do not.

To give you some very specific info,I use this

http://www.paintdocs.com/webmsds/webPDF.jsp?SITEID=STORECAT&prodno=035777241325&doctype=PDS&lang=E

I like it.It was recommended to me at SW when I asked for something suitable for a nitro type finish that would dry hard and quickly...They say it is most often used for bar tops,so that should attest to it's durability.It costs almost $100 for a gallon of the varnish plus the catalyst plus the xylene as a thinner.

It is a finish that you measure out very carefully..3% catalyst.15% thinner for good spray consistency..if it is really warm outside I will use 10% thinner.I make it easy on myself by using horse syringes from tractor supply co to measure it out.I use the big syringe for the varnish,and a small syringe for the catalyst and another small syringe for the thinner..100 ml varnish,3 ml catalyst,15ml xylene...and I mix whatever color I am using in to get the color I want.I use usually 300ml total varnish for each guitar.For the one above I used 100 ml colored amber,100ml colored cherry,and 100 ml clear over the top.

The CA sealer coat you can apply with anything(anything lint free I mean)..I usually use those free business cards you get from vista print to spread it.After the first coat of CA dries,I scuff it and add another,then sand everything level.Do not sand through anywhere because you will see it when you apply your coats of clear.I like the ca because it turns white when you sand it,so it is really easy to see your low spots and if you sand through you will see that too...once I get the sealer coat done and sanded to 220,I start to do the varnish..the 220 scratches on the CA disappear as soon as the varnish hits it,of course,just like any 220 scratches will.

I spray the first 100 ml in thin coats.Then I wait 15 minutes and level sand to 220..use a light touch because at this stage it sands really easily.Then I spray the second 100 ml and repeat the sanding to 220 after another 15 minutes.Then one more time with another 100 ml.

Then I wait 24 hours for full cure and I level sand it starting at 220 and working up to 400,then I switch to micromesh and go through all of those grits,1500 to 12000.

Then I wait another 24 hours and I polish with the stewmac polishing compounds,then i finish the buffing with Turtle wax polishing compound from the auto parts store.

As you can see,it can sound a little complicated,but it is really very easy once you understand the reasons behind what you are doing..

In reality,all you are doing is filling up the wood pores with a sealer(CA in this case),then making that flat,then covering it with a whole bunch of clear and leveling that,then polishing it.Nothing could be simpler,but the work is very consuming,and if you don't do the time,you won't get the result.

[xadioriderx]

im surprised if you go clear you cant see the CA through it! do you buy the CA glue in big tubs then? i spent 9 bucks on a little bottle of it!

very thorough directions though, thank you, i will definitely change my routines!

[westhemann]

No I buy a 4.6 oz bottle of medium CA at a time

http://www.amazon.com/CA-Adhesive-Medium-4-oz/dp/B001I9UMQ4/ref=sr_1_1?ie=UTF8&qid=1317261213&sr=8-1

It seals about 3 guitars.It doesn't take as much as you are thinking...the key is to let the first application dry thoroughly so that seals the grain and keeps the other application from sinking as well.There is nothing to say you must use CA,anyway.Others use thinned 2 part epoxy.I have done that as well.Some people just go straight to the finish and let that seal the grain.That works,too...especially with a high quality finish that cures quickly.

Only reason I don't use "sanding sealer" is because it has poor clarity compared to CA and it tends to sink in over time in my experience on really porous woods like Bubinga.They add stuff to make it easier to sand,but that also makes it softer.

I use a lot of bubinga,so I really,really,really want to make sure the finish never sinks in and starts to show the grain.

This one is a few years old now,and it still looks just like these pics from when it was new,aside from some button rash on the back.