Current:
GTH-1
Completed:
AST-1FB
First Act ME276 (resurrected curb-side find)
ES-5V
Scratchie lapsteel
Custom ST-1 12 String
JBA-4
TL-1TB
Scratch Lapsteel
Meinl DIY Cajon
Cigar Box lap steel
Wishing:
Baritone
Open D/Standard Double 6 twin neck
Finally got back to this guitar after a 5 month break. Lot of problems with paint finish getting dents etc. Anyway today I started on clearcoats. Decided to use spray can nitro - as found poly finish I applied to last build was still soft after 6 months and kept damaging - so thought I'd try nitro again and go for a thinner overall finish this time. Applied first 3 coats (first was a dusting) at 1 hour intervals. 6 hours later - it has already major cracking ... long cracks 15cm+ !
Some around screw holes.
What would folks recommend ?
I would normally be doing a light sand before next nitro coats in a few days .
Will the subsequent coats melt the nitro and fix the cracks ? Or will they still remain. Shoukd I even fine sand yet ?
Didn't have issue like this previously.
I sprayed late afternoon and left guitar outside in evening ( possibly 8 degree temp change thinking about it)
Build has been a nightmare. I'll go back to poly and patience next build
Completed Builds
#7 FS-1
#6 FV-1G
#5 ATL 1SB Thinline
#4 ST1-Jnr
# 3 JBA-4
# 2 LP-1S
# 1 TLA-1R
More likely to be a reaction between the nitro clearcoat and the acrylic paint beneath it (reading back you mentioned the darker green was acrylic so I'm assuming that's what it is).
Never a good idea to mix different paint types. Reading about it, in theory it's possible to do if the first few coats of nitro are very light mist coats that dry as applied and don't go on wet.
It could be due to temperature, though for cracking it's more about the actual temperature and rate of change than a temperature difference over a fairly long period. 8°C isn't a huge temperature difference e.g. 22°C to 16°C. I've had cracking on a nitro finish on a guitar left inside on a stand a very cold (near 0°C) unheated and barely insulated house after the weather suddenly changed, but the cracks were fish-scale sized, not long single lines.
If it were me, I'd sand off the nitro and spray a clear acrylic over the acrylic paint. If you want it hard quickly, then use some 2K clear acrylic (spray outside and definitely use a mask).
Thanks Simon.
That did cross my mind - I read somewhere you could put nitro on an acrylic finish but not the reverse. I agree with you - mixing finishes was probably a bad idea. And thinking about it - was probably 25 to 13 degrees temperature change - over a short time which can't be good
Anyway - I'll do as you suggest - sand it back to the paint and go back to the acrylic spray finish. I've done more sanding on this guitar than all my previous builds together ! But I should be able to remove 3 coats quickly.
As an aside - one of the reasons for the break in this build was because a Dingotone finish on an LP style build from a few years back literally turned into treacle - and needed a lot of patience and goof-off to remove.
Not been a good year for finishes ! But - I must say the LP is lovely with just the "bare" (ish) finish.
Completed Builds
#7 FS-1
#6 FV-1G
#5 ATL 1SB Thinline
#4 ST1-Jnr
# 3 JBA-4
# 2 LP-1S
# 1 TLA-1R
OK I left the guitar for another month to see what would happen.
And I was pretty pee'd off after what seemed to be a disaster.
Cracks definitely all stabilised - nothing more.
Decided today to bite the bullet and sand off the cracked Nitro. But looking at it - the cracks are really kind of cool . I'm a geologist - they look quite like some cracks I see in rocks ... often filled with shiny stuff .
Which got me thinking .... what have I got to lose ?
Filled with a gold paint.
Seems to have worked. Interesting finish.
Question is ... which finish do I coat it with now ? I'm guessing stick with nitro as there will still be some on guitar.. but not sure.
Completed Builds
#7 FS-1
#6 FV-1G
#5 ATL 1SB Thinline
#4 ST1-Jnr
# 3 JBA-4
# 2 LP-1S
# 1 TLA-1R
Good on ya!
Like the old saying: When life gives you lemons... make lemonade!
Making the world a better place; one guitar at a time...
OK I left the guitar for another month to see what would happen.
And I was pretty pee'd off after what seemed to be a disaster.
Cracks definitely all stabilised - nothing more.
Decided today to bite the bullet and sand off the cracked Nitro. But looking at it - the cracks are really kind of cool . I'm a geologist - they look quite like some cracks I see in rocks ... often filled with shiny stuff .
Which got me thinking .... what have I got to lose ?
Filled with a gold paint.
Seems to have worked. Interesting finish.
Question is ... which finish do I coat it with now ? I'm guessing stick with nitro as there will still be some on guitar.. but not sure.
Completed Builds
#7 FS-1
#6 FV-1G
#5 ATL 1SB Thinline
#4 ST1-Jnr
# 3 JBA-4
# 2 LP-1S
# 1 TLA-1R
Yep .... and you know what they say about the definition of stupidity ... doing the same thing and expecting a different result !
But hey ... nothing to lose. Would have a lot of sanding to do anyway.
Completed Builds
#7 FS-1
#6 FV-1G
#5 ATL 1SB Thinline
#4 ST1-Jnr
# 3 JBA-4
# 2 LP-1S
# 1 TLA-1R