Checking on a poly finished guitar?

The Fender guitars of the 1970s had a nitro topcoat over a poly undercoat.Most people assume that it was all poly but that is not the case.I read this in an interview with a Fender custom shop master builder who knows the vintage correct specs.This explains why Fender guitars of that era aged the way they did...a full poly guitar would never age like that.The necks were finished in poly except for the headstock face which was sprayed in nitro and explains why 1970s era Fenders nowadays commonly have a darker headstock face that ambered over time while the rest of the neck is paler.

 

This is incorrect. Fender began experimenting with poly undercoats in the 60's, look up fullerplast. a 70's guitar is all poly except for the front of the headstock. Poly will age and check. It usually takes more abuse though.

 

My Japanese electric is from the 60s and has a poly finish (a very thin one, but still poly). My thermostat went wonky last week and the heat was stuck on while we were gone for a day, house went from 62 in the morning to around 78, then without thinking about it, I opened the window in the room the guitar was hanging in, dropping the temp down to around 60 in an hour. These fluctuations left me with a few big cracks down the front of the guitar (with the grain). Being a really curvy offset body guitar they look more like stretch-marks than traditional nitro checks.

 

Ouch. Bummer

 

Could have been a lot worse, I had two acoustics, a bass, 4 electrics a banjo and two mandolins (one 100+ years old) in that room and the old Japanese was the only instrument effected, so I counted myself lucky.

Last time something like this happened I lost 2 flats full of seedlings for my garden, set me back around a month and I ended up having to buy tomato and pepper plants from the store.

Our house has terrible wiring (120 year old farmhouse), we usually have something like this happen once a year.

 

The guitar in question looks like a Tele Custom in a natural finish. I have a '73 and mine is black, and most definitely poly. But I have seen other Tele Customs, all with sunburst finishes, from as late as 1975 that have nitro finishes and we've seen several photos on the forum here of nitro finished Customs. Now, I know what all the usual literature says, but I've seen these guitars and I know better! It wouldn't surprise me at all if a natural finished (which is transparent like a sunburst) Custom from '73 was nitro finished.

 

Isn't there a quote from a fender employee floating around that says they used nitro clear over a poly color coat up until the late 70s when they switched to full poly color and clear coat?

 

I don't remember the details, but I think you are 100% correct.

Forum member "Slack", who is one of the few true experts around here, has 2 or 3 sunburst Tele Customs from the mid 70's with nitro finishes.

 

poly does age just not as fast or as subtle as nitro. whomever said it doesnt age is wrong. There are tons of examples, check out Yngwies Duck Strat.

 

Poly finish will crack, but it doesn't check like that.

 

I found the quote I was thinking of. I copied and pasted this from another forum discussing the same topic.

"Cut and pasted from another article I found a couple of years ago. I do not know the origin. For those who do not know, Mr. Kendrick is a longtime employee and masterbuilder at Fender.

-----------------------------------------

Pardon my typos. I've lost alot of brain cells in my day. Could it be the 'Nitro'.

The first Fender lap steel was finished in black enamel. When Doc Kauffman and Leo formed K&F guitars in 1945, their original instruments, including the amplifiers, were finished in a lead based, wrinkle coat enamel. A nice shade of Battleship Grey. That was the only color available. After expermenting with different woods other than pine for guitars, they began using nitrocellulose lacquer. They used what was available to the furniture trade at the time.
The original colors were blonde, sunburst, etc... just like your Grandmas coffee table.

Custom colors were introduced in 1955. Once again they were enamel. The same material they used in the auto industry. The enamel would not adhere to the stearate based nitocellulose sanding sealer. Acrylic lacquers were then developed by Dupont to be sprayed on material other than metal. "Duco colors". In order for the paint to adhere, Fender began using a Sherwin Williams product called Homoclad. It was a penetrating, heavy solid, oil based sealer used as a barrier coat to to provide better adhesion for their guitars with custom colors. It was applied by dipping the guitar bodies directly into a 55 gallon drum, filled with the product. ALL Fender guitars produced after 1955 used this product until 1967, when Fender began experimenting with polyesters an undercoat.

By 1968, virtually all Fender guitar products used polyester as an undercoat, including necks. It's a two part product using Methyl Ethyl Ketone(MEK) as a catalyst. The reason the face of the pegheads were not sealed with polyester, is because type 'C' decals (under the finish) would not adhere to the product. While it is true a few guitars may have squeaked by with homoclad, when homoclad wasn't available, they used a Fuller O'Brian product called Ful-O-Plast. PLASTIC!!! It's obvious to me that those necks or bodies were stragglers, having to be reworked for some reason or another and not shipped after the change.

I'd like to make one thing clear... ALL FENDER GUITARS PRODUCED AFTER 1968 HAD A POLYESTER UNDERCOAT WITH A LACQUER TOPCOAT!!! There is no specific ratio. Enough poly was, and is sprayed to properly fill the grain while preventig a burn through while sanding.

In 1983, Fender began using polyuerthane as a topcoat. It cured quicker. It had better clarity. It had more depth and gloss, and didn't melt when you accidently spilled 151 on it. Fender then discontinued the use of polyester on the necks. Polyurethane is a 2 part product using a catalyst.

Fender has continued to use polyester, polyurethane, nitro, homoclad, and Ful-O-Plast.

Nitro is not a superior finish. An electric guitar doesn't 'breathe' at 120 db.

My first year at Fender I personally painted approximately 46,000 guitars. I like polyester. I like Nitro colors too. But maybe I'll let the players that use poly (ester or urethane) speak for themselves...

Billy Gibbons, Geddy Lee, Alex Lifeson, Joe Perry, Jimi Hendrix, Eric Clapton, Roccco Prestia, Jimmie Vaughn, Nils Lofgren, Vince Gill, Chet Atkins, Tom Hamilton, Lenny Kravitz, Merle Haggard, Don Rich, Darryl Jones, Mike Stern, Larry Carlton, Peter Frampton, Sting, Marty Stuart, just to name a few. More are available upon request.

Hope this helps,

Mark K."

I was always curious about this cause my 78 Tele has checking on the body that will disappear and reappear at random. Makes no difference to me cause I love the guitar, but it's an interesting topic that I've always been curious about.

 

Wel, Mark Kendrick certainly knows what he is talking about, but I am pretty sure that my '73 Tele Custom is all poly. I mean it has a ding or two on it, but no checking whatsoever and most of the finish looks brand new. And it is also well documented that after CBS took over, polyester finishes were brought in as they were more stable, produced less toxic fumes, dried faster and were therefore better suited to mass production. By the early 70's Fender's catalogs were saying "Fender thick skin™ high gloss finishes provide Fender instruments with an outer beauty that is both durable and attractive".

My understanding is that in the 70's only some models retained nitro finishes. Prior to this post I had only seen nitro finished 70's Tele Customs in sunburst. I think I'll probably have to add "Natural" to that.

 

Lol. How times change.. they literally call it the opposite now..

 

Wish my '69 body would check like the neck...
I knew a guy who was a plastics expert (toy industry) and he explained to me that plastic molecules tend to line up, almost in stripes.
That's why a lot of plastics (like sour ball wrappers) tear easily in one direction, but not the other.
I always assumed that's why cracks/checks in poly tend to be long and all in the same direction.

 

i love that quote because its Fender and the CS that say guitars breathe.

 

Read what Mark Kendrick(Fender custom shop master builder)had to say in the above post by Scotticus(post #13).He quotes 'all Fender guitars produced after 1968 had a polyester undercoat with a lacquer topcoat'.That is consistent with my initial post.

The 1970s era Fenders have aged nowadays in the typical way that nitro ages(the top coat of course).Poly finished guitars don't age the same way.Early 1980s guitars finished in poly have proven over several decades that their aging process differs from a typical nitro aging....they still retain thier plasticky look with typical chunky dings as opposed to a nitro's smoother,faded aging.

 

I don't think anyone can predict how poly and nitro will age because each instrument can be exposed to limitless weather and playing conditions:

An early '52 reissue, poly finished, cracked:



My '64 JM, nitro, no cracks:

 

Maybe I was a bit harsh for just saying you were incorrect Sonny. I apologize for that.

We do know that Fender used lacquer on the headstock face, hence the reason it ages differently than the rest of the neck that is only finished in polyester. I am not going to say that 70's guitars do, or do not have a nitro clear coat, because I was not there.