humidity issues / finishing alder with tru oil

[frustrated_jazzman]

Hi everyone, I'm thinking of starting on my 2nd warmoth guitar project, and this time it's gonna be a stratocaster type (first project was all mahogany HH tele, neck and body finish by warmoth). To minimize cost, I'm thinking of doing the body finish myself using tru oil. I've read a few posts/seen a few videos about the process and it seems quite simple even for the inexperienced. I understand that too much humidity can be an issue when finishing a guitar body. I plan to do this in my home studio where I have a dehumidifier which I can run 24/7 at least during the finishing/drying. With the dehumidifier, I can maintain relative humidity levels to around 55 (humidity here can go up to 85 on rainy days, average is 75, on good days 63).

a few questions:

1. Is 55 relative humidity dry enough to do a tru oil finish? Would it be better to turn the aircondition on (together with the dehumidifier) to achieve lower humidity levels (around 40) during the process? As I can not run aircon 24/7 condensation might be an issue?

2. I do not really wish for a glossy, shiny finish. All I'm after is enough protection for the wood so it does not suck up any moisture from the high humidity ( and all the sweat it can get from playing), so how many coats is enough for moisture protection?

3. I plan to do this on an alder body (my neck is most probably a one pc maple satin nitro finish). What is the best/easiest wood to use for tru oil?

4. I'm getting a wilkinson tremolo rout for this project. Is it okay to have the studs pre-installed before doing the tru oil finish?

Thanks in advance for the advice.

 

[bagman67]

a few questions:

1. Is 55 relative humidity dry enough to do a tru oil finish? Would it be better to turn the aircondition on (together with the dehumidifier) to achieve lower humidity levels (around 40) during the process? As I can not run aircon 24/7 condensation might be an issue?

It's dry enough.  Tru-oil cures faster when it's dryer, but 55 is not unreasonable. 

2. I do not really wish for a glossy, shiny finish. All I'm after is enough protection for the wood so it does not suck up any moisture from the high humidity ( and all the sweat it can get from playing), so how many coats is enough for moisture protection?

Just a couple coats will do it.  Give the body a little love with 220 or 320 sandpaper to make sure it's evenly sanded.  Warmoth is usually perfect out of the box, but you can't be too paranoid when it comes to finishing.  Dust off, use a blower if you have one, and then wipe the body with a liberal splash of naphtha so you will be sure to remove finger grease and any other surface contaminants. 


When using the product, pour it from the bottle into an open container like a small bowl.  I generally just pierce the foil and squeeze it out, and then recap the bottle.  Seal tightly and store the container upside down to reduce the likelihood of it curing in the bottle.


Start with a thin coat - you can thin Tru-Oil with mineral spirits.  Start with a 50/50 mix.  Once that coat cures - about 24 hours - apply it full strength every 24 hours for two or three days, and then give it a few more days to cure completely. Rough it up a little between coats with 320 sandpaper or 000 synthetic steel wool and another napththa wipe.  I personally avoid real steel wool because it leaves tiny little bits of itself behind, which is a mother to get rid of.  If you feel like you want more, go for it.  If you want to dull it down, use synthetic steel wool - the white (0000) or grey (000) pads.  Green and maroon grades are very aggressive and will probably just scrape the finish off completely.  THing about Tru-oil is you can always sand it back a little and add more, boom.  I just described the entire repair regime, right there.


Some folks use coffee filter paper to apply the oil,  others their fingers, others use a French-polishing pad, aka a tampon (no, really, look it up).  I used to be a coffee filter man, but have moved over to the tampon school.  To make one, take two six inch squares of old t-shirt.  Wad  one up, place it in the center of the other, and pull the corners together and twist.  Tie off the bundle with string or rubber band.  Dip the tip of the tampon in your container of oil, and commence to spreading the product on your part.  Some folks do a full French-polish type application this way, but I don't go that far. 


Safety tip:
When you're done applying the product, open your bundle and spread the cloths out and let them dry.  Start with new tampon for your next day's application.  Tru-oil cures through polymerization, which is exothermic (i.e., it generates heat).  It can spontaneously combust if you leave the rags wadded up.

3. I plan to do this on an alder body (my neck is most probably a one pc maple satin nitro finish). What is the best/easiest wood to use for tru oil?

Alder is fine, as is maple.  It's tight-grained so you won't need to worry about the wood pores being really obvious.  You can work with ash, mahogany, limba, other open-grained woods, but you need either a dedicated grain filling product or you need to spend a lot more time applying and sanding Tru-oil if you want an even, non-porous finish.  The product is not well suited to rosewood or other oily, tropical hardwoods but that doesn't sound like an issue for you anyway.

4. I'm getting a wilkinson tremolo rout for this project. Is it okay to have the studs pre-installed before doing the tru oil finish?

Yes.  If you really want to be cautious, you could drive two screws of the appropriate thread into the stud holes, but I applied water-based dyes and Tru-oil to this maple-topped body without protecting the studs:

 

[frustrated_jazzman]

Thanks for the helpful advice Bagman67. Did you dye your wood before applying tru oil? I'm thinking dyeing the alder a little to make it darker might look better. Is dyeing advisable on alder, or not necessary?