refinishing a warwick..

ollybarclay · #1 10-05-2006, 06:49 AM

so i got a corvette from a friend dirt cheap - for a reason.

it's a natural finish, no laquer/paint. it's obviously not been treated that well, sounds great, but aesthetically it's been through the wars.. i'll post some pics tonight.

basically, i don't have the nerve/expertise to resand the body or anything like that...anyone know of anything that can be done fairly cheaply to liven up the body?

S Lewis · #2 10-05-2006, 06:51 AM

stickers

lots of them

Kronos · #3 10-05-2006, 07:12 AM

Most higher end warwicks are a natural finish. How badly dinged up is it?

vindy500 · #4 10-05-2006, 07:18 AM

Get the sandpaper out, its no difficult,

Beav · #5 10-05-2006, 07:28 AM

I'd start with steel wool before sandpaper.

Post some pics too.

ollybarclay · #6 10-05-2006, 07:31 AM

Quote:

Originally Posted by Kronos

Most higher end warwicks are a natural finish. How badly dinged up is it?

there's a good few 'belt rash' scratches on the back, a small chunk missing from the lower horn, both straplock screwholes have been 'sheered' i.e. there's no thread on the inside of the wood, and my straplocks don't fit with a bigger screw that WILL bite into the wood..

the wood should be this colour:

but is basically just much dirtier/grimier...maybe i should just break out the sandpaper, but i don't want to!

edit: i will post some pics when i get home from work tonight

HotTubesGrooves · #7 10-05-2006, 10:09 AM

The straplock thing is easy to fix - insert a matchstick into the hole and break it off so its level with the hole face. Screw your straplocks on and the matchstick will push outwards and secure it - I did this on my old Warwick and you dont even need to put glue in there.

ollybarclay · #8 10-05-2006, 10:56 AM

i've tried the matchstick thing before, only works for a short while before the match stick grinds away to splinters..

anyway, pics...

as you can see, gaffa tape to keep the strap on in the guitar was resorted to...should i just get out my sandpaper? bearing in mind the remaining glue from the tape is still kinda sticky..?

the bottom pic also shows off my lovely carpet and the small chunk of wood missing, at the very left hand side of the small horn..

superjesus · #9 10-05-2006, 11:37 AM

i doubt you'll do any further damage trying to clean the bass with naptha (e.g. lighter fluid) to remove any of the tape adhesive.

If the matchstick strap button fix isnt working for you, i recommend wood glue and a dowel rod cut to length. Redrill the hole through the center of the dowel with the appropriate size bit.

62bass · #10 10-05-2006, 07:04 PM

Yes, clean it up first with naptha or paint thinner. That'll get rid of the adhesive. The chip can be fixed by gluing in a small sliver of wood and sanding it down to shape and it will probably not show after refinishing. Judging from the picture it looks like you may even be able to sand it out without ruining the contour of the horn.

To do a good job you should sand down to bare wood, then apply a number of coats of one of the tung oil type finishes. You'll get all kinds of recommendations on which one is best in the next posts.

Once it's cleaned up though, you may be able to get away with just using one of the dull looking tung oil finishes like Warwick used. Someone here may know what it is they use at the factory. That would save a lot of the work of sanding down to bare wood.

Use a fine sandpaper-220 grit aluminum oxide then 320 grit to get it really smooth.

Myself, I'd go all out and refinish it with a more protective finish. But that's me.

Joe Gress · #11 10-05-2006, 07:49 PM

Um, I jammed wood filler into my screw hole when my strap button fell out.

Jazzdogg · #12 10-05-2006, 08:29 PM

The fact that it's a bolt-on will make the job MUCH easier.

I'm a furniture and cabinet maker who teaches college-level woodworking by day and plays bass at night.

I'll try to post some instructions for you, but because of the file size, I may have to parse it into two (or more) separate posts.

NOTE: These instructions were written for students applying an oil finish to raw wood; you can adapt many of the methods to a refinishing job, but that wasn't the original intent of these instructions.
************************************************** ****************

SURFACE PREPARATION

DENTS & CRUSHED FIBERS:
Damage to a work piece during the construction process seems all but inevitable. A dent (compressed wood fibers) can be repaired by applying moisture and heat directly to the dented area, causing the wood fibers to swell and expand to almost their original volume.

Start by lightly scraping the dent and the area immediately surrounding it. Then, apply a few drops of water directly to the dent and allow it to absorb into the wood fibers for a few minutes. Next, dampen a small area of a clean cloth and apply it directly over the dent.

Using a clothes iron set to high, apply heat to the dented area through the moist cloth with the pointed tip of the iron, taking care not to press the iron into the wood. Avoid the temptation to lie the iron flat against the wood -- the objective is not to “iron the wood,” it is to apply heat and moisture only to the dented area in order to achieve localized swelling of the wood fibers.

SCRAPING AND SANDING:
People tend not to notice perfection, but readily notice imperfections: an award-winning project depends as much on the avoidance of conspicuous faults as meticulous joinery and application of finishes. When a finish has been successfully applied, people will have an urge to touch your project; to have their sense of touch confirm what their eyes have observed, and to fully appreciate the tactile qualities of the surfaces.

It makes sense for the artisan to employ these same senses during the finishing process. Use your fingers to inspect the prepared surfaces; can you feel defects or irregularities that may be observable when finish is applied? Installing an inspection light at an angle to the work piece will cast shadows that will exaggerate surface imperfections; once found, they can be corrected.

One of the most common finishing errors is the failure to completely remove mill marks before sanding commences; these kinds of imperfections will be amplified when the finish is applied. This is because the scalloped surfaces presented by mill marks expose segments of end-grain which absorb stains and finishes at a different rate than face or edge fibers.

Scraping or planing removes mill marks quickly, leaving a surface that is ready for 200-grit abrasives.
Sanding is necessary to prepare the wood fibers to receive a finish. Abrasives cut across the wood fibers, creating a condition in which the wood surface is analogous to myriad wicks, thirstily absorbing and finishes, and allowing them to penetrate the wood fibers more-or-less evenly and uniformly.

When surface preparation relies solely on sanding (surface is prepared without scraping or planing), it is important to progress through the following grits in sequence:
120
150
180
220

TO BE CONTINUED...

Jazzdogg · #13 10-05-2006, 08:30 PM

OIL FINISHES:
The two oils commonly used in the manufacture of oil finishes are linseed oil and tung oil. Linseed oil is derived from the flax seed, while tung oil is extracted from the nut of a tung tree. Without further treatment, these oils would dry too slowly to make them suitable as modern wood finishes.

Metallic driers are added to Linseed oil, which is then heated, resulting in product commonly known as Boiled Linseed Oil (a misnomer). Tung oil is heat treated to achieve polymerization (a state in which the molecules are bound together in long strands).

After experimenting with many oil finishes in search of a product with desirable characteristics, Liberon Finishing Oil (a tung oil-based product imported from England), was selected as the best oil finish. It seems to have a shorter drying time than other oil-based finishes. Minwax Antique Oil Finish (in the red can) also provides acceptable results, although it does not dry as quickly as Liberon Finishing Oil.

NOTE: It should be noted that an oil finish, while very suitable for the exterior of fine furniture projects, is not recommended for the interiors of cabinets, drawers, et al. Even with ample air circulation, an oil finish will not cure properly, and an unpleasant odor will linger long after the project has been completed.

SPONTANEOUS COMBUSTION:
Before describing the process of applying an oil-based finish, a discussion of spontaneous combustion is warranted. Simply stated, spontaneous combustion describes [oil-soaked] materials bursting into flame: a very dangerous condition that should be avoided at all cost.

Three components are required for combustion:
• Fuel
• Oxygen
• Heat

An oil-soaked rag provides the fuel, and there is abundant Oxygen in the atmosphere. As oil products polymerize, all of those little molecules racing around and bumping into each other generate heat. A rag lying flat readily gives off this heat to the atmosphere and combustion temperature is never achieved. However, in a folded rag the heat is not allowed to dissipate -- it is concentrated in folds and pockets, and the temperature continues to increase until combustion is achieved.

Because spontaneous combustion is so likely, and the dangers so severe, caution should be exercised to prevent an occurrence. This is achieved by closely monitoring all oil-contaminated products during use (never leave an oil-saturated applicator unattended), and by promptly disposing of oil-soaked rags, unfolding them and spreading them flat on a concrete or dirt surface, away from all combustion sources, until completely dry.

When the oil has thoroughly dried, you are left with a “rag Frisbee” that can be safely placed in a trash container.

APPLYING AN OIL FINISH:

OVERVIEW
Applying an oil finish with wet-or-dry sandpaper creates a slurry of oil and sawdust that will fill the pores of open-grained wood; properly applied, a sanded-in oil finish will achieve a glass-smooth surface. One of the benefits of an oil finish is that there is no need to finish an entire project at once, or to maintain a wet edge. You can stop and start as you please, as long as you thoroughly remove excess oil before it becomes thick and unworkable.

After dry-sanding to 220-grit, prepare silicon carbide wet-or-dry sandpaper in three grits:
• 220-grit
• 320-grit
• 400-grit

MATERIALS NEEDED
• Finishing oil
• Silicon carbide (wet-or-dry) abrasive cut or torn into eighths, and folded in thirds.
• Clean, lint-free, absorbent rags (old t-shirts work well).

THE APPLICATION PROCESS
Wet the wood surface with finishing oil, rubbing it in with your hands until the surface fibers are saturated. I keep my finishing oil in a squeeze bottle (with an airtight lid), for easier and better-controlled application.

Start with 220-grit and sand the oiled wood, with the grain, until a slurry of oil and sawdust is created. Once a slurry has been created you can sand in circular or figure-eight patterns. Work one small area at a time, until the surface is consistently smooth and the slurry has been packed into the open pores of the wood.

After several minutes, the surface(s) you have been working will be consistently sanded to 220-grit, and the slurry will have begun to thicken. Next, wipe all remaining slurry from the surface of the wood with a clean, lint-free, rag. This needs to be accomplished before the product becomes too dry and gummy to remove easily - with Liberon Finishing Oil you have about twenty minutes. With other oil finishes, such as Minwax Antique Oil Finish, you have a little longer - perhaps three-quarters of an hour.

You will need to monitor your project for bleed-back over the next few hours. Bleed-back is the term used to describe residual oil that will ooze up to the wood surface from the pores as the finish polymerizes. Bleed-back will appear as small dots of finish on the surface of the wood.

Inspect your work once an hour, wiping away bleed-back with a clean rag. Then allow the first coat to dry for 24 hours before proceeding.

After waiting a full day, repeat the process with 320-grit. Following another 24-hour curing period, repeat the process with 400-grit, and allow the oil to cure for at least a week before applying two thin coats of hard paste wax, waiting five or ten minutes before buffing with a clean, white, lint-free cotton rag (old t-shirt).
********************************

Please let me know if you have questions.

Joe Gress · #14 10-05-2006, 09:07 PM

By no means am I trying to hijack the thread, but thank you very much for that tutorial. I'm going to build my own bass with a tung oil finish, and that is probably the most helpful tutorial that I have read so far on the topic. I have one question though, is their any thing that I can do to insure that the end product will be most defiantly "glass smooth"?

Jazzdogg · #15 10-05-2006, 09:29 PM

If you apply a sanded-in oil finish properly, it will beg to be touched, look spectacular, and best of all, be easy to repair.

Whatever you do, don't try to use "pure" tung oil - it takes forever to cure.

I'll see if I can attach a snapshot.

Joe Gress · #16 10-05-2006, 09:33 PM

Ok, I will have to look for the one that you described in the tutorial. Can I get it online?

Jazzdogg · #17 10-05-2006, 09:41 PM

A Google search turned up several sources, including this one:

http://www.rockler.com/product.cfm?p...+Finishing+Oil

If you want a glass-smooth finish, follow the instructions I posted instead of the ones on the can.

BTW, when I apply a sanded-in oil finish, I don't stop at 400-grit; I work my way through 4 grits of wet-or-dry abrasive, each a day (or more) apart: 220-, 320-, 400-, and, finally, 600-grit.

The most common mistake students make when attempting a sanded-in oil finish for the first time can be traced to impatience: they fail to allow the wood to absorb as much oil as it can before they start sanding. "Patience, Grasshopper..."

Joe Gress · #18 10-05-2006, 09:46 PM

Thanks. I went and copied your instructions on to my computer so that I will still have them.

What about the wax in the end, is their a good product that you can recommend?

BassGreaser · #19 10-05-2006, 10:31 PM

if I may ask a question..... is it possible to just apply coats of hard paste wax with out applying an oil finish?

Jazzdogg · #20 10-05-2006, 10:52 PM

Quote:

Originally Posted by BassGreaser

if I may ask a question..... is it possible to just apply coats of hard paste wax with out applying an oil finish?

Generations ago, wax and animal fat were among the few "finishes" applied to wood because better stuff hadn't been invented yet.

Nowadays, there's no reason to subject a valuable bass to a finish as impermanent and permeable as wax, although no one is going to send the finishing police to visit if you choose to do so.

Wax provides very limited protection. The natural acids in your skin and the friction of your bass rubbing against your clothing will degrade the wax, leaving you with a very inconsistent finish, appearance, and protection. When you consider these elements, as well as the effects of hot lights and the occasional spilled cocktails, wax doesn't look too good as a bass finish for a gigging musician.

Additionally, if you apply wax to raw wood, you are effectively limiting your ability to apply a different finish later because the wax acts as a "resist;" other finishes can't be applied over wax.

Were you to make a bass out of an oily tropical wood like cocobolo, you could probably get away with no finish except a hard carnauba wax; that would be a beautiful, and HEAVY, axe!

We have a fantastic woodworking program at Palomar College (one of the very best in the U.S.A.), which is conveniently near you in sunny San Marcos. If you have time, check us out!

www.palomar.edu/woodworking