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Hi guys.
I finished this neck about 4-5 months ago. Finish is Duplicolor clear.
It's a nice piece of flame maple. When the finish was buffed out it was absolutely beautiful, but about a month ago this began appearing. And spreading.



Finish is still smooth and glossy, and this effect disappears as I turn the neck, but it looks like something is happening to the wood itself underneath the finish.
Has anyone experienced this and or does anyone know what the problem is?
Thanks.

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Mike

The only thing nescessary for evil to thrive is for good men to do nothing.

How thick is the finish? It could be crazing due to excessive film thickness.

what sealer did you use? Also if you over sand the wood you can burnish it and the finish will have adhesion problems. After 13 yrs of building and finish I learned this , 220 grit is plenty fine as you need a little tooth for the finish adhere . Also shellac is not a good sealer and more and more finished don't adhere well to it . I have found that you may not find that out for years .
Always use the recommended sealer that the finish manufacturer recommends.

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John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

My guess is the finish is a bad product.
Got sandpaper?

Never used Duplicolor on wood. Since the time frame puts the finish being done in June or July, could be humidity/EMC related. Perhaps the Duplicolor is too rigid and will not allow for the slight seasonal expansion and contraction of the wood.

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Brian

You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/

Thanks, guys. Sanded to 320. No sealer. Finish is pretty thin.
Also, the finish itself is still smooth. I believe this is going on under it.
It is possible that the finish is shrinking into the figure in the grain, but it would seem that I would see this in the finish itself. If you run your hand over it, it's smooth as a baby's bottom. And if you hold it up to the light, you can see a nice, smooth, glassy finish, with no cracks, pits, crazing, or anything else.

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Mike

The only thing nescessary for evil to thrive is for good men to do nothing.

Did yu use an undercoat? Perhaps the undercoat is crazing but the top coat is still good.

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Old growth, shmold growth!

No undercoat. Just Duplicolor lacquer straight on top of the maple.

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Mike

The only thing nescessary for evil to thrive is for good men to do nothing.

Usually, when finish shrinks down to the grain - it looks corrugated on top, but it is still just as clear and beautiful as it was previously.....

In this case - it looks like the finish pulled away from the wood.... so there's a slight gap between the wood and the finish...

I suppose the other thing that could be happening is maybe the lacquer is too brittle - and it's cracking at key neck movement places..... While I don't have any first hand experience with Lacquer - the reading I have done points towards the need to use a little plasticizer to keep it from getting too brittle and crazing... One solution I saw referenced was a bit of castor oil into the lacquer...

I might suggest doing what John Hall suggested - leaving your wood finished a bit rougher - like 220 grit to give the finish something to bite into.... You might also look at letting that 1st coat onto bare wood have longer to sit to gas off the residual thinner that soaks into the wood before shooting coat #2.

Thanks

Mike,
Do you have an idea as to how long the wood has been drying/acclimating?
That`s what I would suspect.
Now that I look at it closer, it kinda looks like a fungus amungus!
Coe

_________________
Give me 50 cents worth of regular.
Check my oil too, if you don`t mind,,,

Thanks, guys.
To answer a few questions, no, I don't know how long it's been drying/acclimating, but it sat stickered in my shop 6 months before use. I have another neck built from the same board that is waiting on warmer weather for finish, and another piece of it that's going on near a year in stickers. It's a beautiful piece of wood that I'd love to use, but this one has kinda got me worried.
Coe, I have had more than one person mention the word fungus.
If I haven't resolved the problem sooner, when warm weather hits, I'll strip it, bleach the living tar out of it, and refinish.

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Mike

The only thing nescessary for evil to thrive is for good men to do nothing.

I have noticed that lacquer behaves differently when curing on surfaces that are concave, convex or flat.
Lacquer curing/shrinking on a convex surface such as the neck shaft, for example, MIGHT be more prone to microscopic seperation.
I doubt that this is the cause of your issue, Mike, but possibly a contributing cause.
Sorry you had to have this problem.
Nelson

Strip it and get yourself some of the Cardinal nitrocellulose lacquer. Lots of great reports on it. I'm ordering a can just to try it. Folks seem to be going to it in lieu of the Seagraves because Seagrave's seems to have changed McFadden's formulation.