Official Luthiers Forum!

Good morning,

Has anyone on the forum fully completed an acoustic guitar finish using HP Topcoat? (Not EnduroVar)

I am halfway through applying it on an OM-35 style build and was looking for any feedback others may have in regards to their process.

Currently, I am applying 3 coats a day 2-3 hours apart and sanding with a fine 320 sanding sponge between coats. The goal is 12 coats let sit for 21 days then start finish sanding and buffing.

Thank You,

Ray

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Guitar Building = Continuous Improvement Process

I have used it on furniture - 3 coats, level sand, 2 coats, 600 grit, polish up through the grits. I have never made it mirror like, but see that it can be done. Easy on a flat surface. I am right now using Min-Wax Wipe On Poly on a guitar (with a similar schedule) for the first time and it is going well.

Ed

Follow up on General Finishes HP Top Coat:

Very happy with the results after final buffing of this product! Easy to apply and easy to finish to a nice glossy shine.

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Guitar Building = Continuous Improvement Process

I don't believe you. Where's the pics

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Hutch

Get the heck off the couch and go build a guitar!!!!

Absolutely!

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

Alrighty, is there a simple way to transfer photos from a Samsung phone to this thread?

I sent a pic to Jeff Jewitt last night to ask him some advice and he responded right away! Really cool.

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Guitar Building = Continuous Improvement Process

Disregard

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

Raymund,
PM'd you but you haven't picked it up yet.

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

RaymundH had problems with his phone and asked me to post some images for him.

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

Nice one Raymund!

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

Looks great!

You sprayed?

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I'm not a luthier.
I'm just a guy who builds guitars in his basement.
It's better than playing golf.

Big thanks to Colin for the help on the pics!

This is the process I used:

Day 01

Foam brush two coats of General Finishes Sanding Sealer two hours apart. (scuff sanding with 320 sponge pad between coats)

Day 02
Brush 4 coats of HP Top Coat two hours apart scuff sanding with 320 sponge pad between coats

Day 03
Brush 3 coats of HP Top Coat two hours apart scuff sanding with 320 sponge pad between coats

Day 04
Brush 3 coats of HP Top Coat two hours apart scuff sanding with 320 sponge pad between coats

Day 05
Brush 2-3 coats of HP Top Coat two hours apart scuff sanding with 320 sponge pad between coats

I let this cure for 21 days while I worked on the neck

DRY sand with P400,P600,P800,P1000,P1200,P1500,P2000. I did this by hand over about a two hour time period and a couple beverages.

Used a random orbital sander with 3 Surfbuf pads to polish:
Started with Menzerna 2L Paste followed by 16 Paste and finishes with Liquid Polish. http://www.woodessence.com/Menzerna-Pol ... 91C15.aspx

Instead of applying the Menzerna polish directly to the pads, I applied a small amount of product to the body and buffed in small sections. Found applying to the pad directly very messy as product flew all over the room! Also, I used a dedicated pad for each level of paste.

Keep in mind that although this a durable finish, you can still burn through it if you use a heavy hand on the sander!

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Guitar Building = Continuous Improvement Process

I was looking online today for an alternative to the compressor and I found an airless gun for $59 that got rave reviews. I'm going to try it, just not sure what water borne paint I'm going to use yet. That's still a long ways off for me. Why brush if you can spray for this cheap? Less time, less sanding and spraying is just fun for me.

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Hutch

Get the heck off the couch and go build a guitar!!!!

Frankly, it only takes about 5 min to brush a body with thin coats. As a hobby builder, I can apply in the house shop anytime with no need for a booth or good weather if you spray outside. $8 dollars for a bag of 3" foam brushes and no clean up. As for the sanding, you will have to scuff sand between coats no matter how you apply to get a mechanical bond. (as per manufactures directions)

Now, if you are fully geared up for spraying, then I think that would be the way to go for you. Although, I believe you would have breakdown and clean your gun between coats for water borne finishes??

This is the 5th different finish I have experimented with and find it the best....So far. ;o)

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Guitar Building = Continuous Improvement Process

WB finishes can be safely sprayed in the house where it's always warm and comfy. No need for a booth either. I would do it right on my bench in the basement with a dust mask on.

I have used the GFHP with a foam brush on a counter top edge and it worked very well. I still prefer to spray and if I had the sprayer at the time, I would have used it for that.

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Hutch

Get the heck off the couch and go build a guitar!!!!

RaymundH,
That finish looks very nice. Thanks for sharing the pics and your process. Did you use the finish straight from the can?

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George :-)

George - Yes, straight out of the can. Try not to back brush to much as you can fix any little runs or ridges with the light scuff sand between coats.

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Guitar Building = Continuous Improvement Process

Looks great. Did you fill the grain before? If so, what did you use?
Kent

Pore Fill:
Day 01
Full coat of Z-poxy applied with a Bondo scraper.
Day 02
Light sanding with maroon synthetic steel wool. Used this instead of 0000 steel wool to negate any potential for steel filings embedding in fill.
Full coat of Z-poxy applied with a Bondo scraper
Day 03
Light sanding with maroon synthetic steel wool until fill is nice and level
50/50 mix of Z-poxy and methyl hydrate as washcoat
Day 04
Sand level and smooth with maroon synthetic steel wool.
Start Finish.

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Guitar Building = Continuous Improvement Process

You know, that looks pretty dang good for any finishing method, far less a low tech approach.

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

+1

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Hutch

Get the heck off the couch and go build a guitar!!!!

That worked!

Good job!

Thanks guys. It was a pretty easy process to follow and I’m definitely going to use it on the next one.

The fun part about this build is that this is only half the experiment on the project. The other part is on the inside!!! ????

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Guitar Building = Continuous Improvement Process

If you're talking about hearing how the sound turned out, that's my favorite part!

New username, same ole Pat Macaluso!

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Pat

Not yet.

Although, I am extremely curious to see how this bracing system sounds in hand made guitar.

V....

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Guitar Building = Continuous Improvement Process