Do you buy warped Promo's and can you straighten them?

[HotRodaSaurus]

Says it all in the title really.

Can they be straightened or is the main use for these the chrome parts which do not appear to warp. I I have a decent acetate body can it be prevented from warping these days.

[gtx6970]

No. I don't buy them.

I haven't heard of anyone fixing them

[Howard Cohen]

If the promo is an old piece from the late 1950s to early 1960s, it is almost impossible to fix it. The problem is not warping but the plastic breaking down. The old plastic was very porous, filled with miniscule air bubbles, and as the promo sat, the air bubbles would burst and the air would escape, thus causing it to change shape. It may look warped but you cannot reshape it back to it's original shape. The best way to stop it from changing shape is to disassemble the promo and coat all the painted/molded in colour parts with a clear coat, thus sealing the plastic. You will notice that it is very rare for the chrome plated parts to change shape, that is because they are coated. The plastic changed about 1960/61 for most promos and the problem stopped.

(this explanation was given by the late John Hanley many years ago)

Edited June 22, 2015 by Howard Cohen

[disabled modeler]

Depending on just how and where its warped at but for the most part it will never be straight again...the plastic they used is the reason. I have fixed some but never could get them close enough. I have a few that look like a banana and there is just no fixing them...good for parts or...? once they are that way. They get brittle too to the point of thin glass almost...too bad I really like them.

[HotRodaSaurus]

Thanks all, I had been offered a small collection but all were warped, one of them, a 1959 Cadillac is not just smiling, it's almost laughing. Nothing spectacular in the collection, just the usual JoHan Cadillacs, a few Buicks and an Olds

[Bob Ellis]

There were made of acetate material. Most have warped, though miraculously, some stayed straight.

These include; pre-1964 Johan and pre-1961 AMT/SMP. Some of the 1961 AMTs are bad but not all.

Not sure why they used acetate except it molds nice and shiny?

[Bob Ellis]

According to eye glass ware people; Acetate is stronger and less brittle. Also, acetate doesn't need painting like other plastics to have a nice appearance and shine.

This makes sense. The wanted to make promo cars that kids could thrash around and looked nice out of the box.

[Ramfins59]

I've bought and reworked, or will rework close to 2 dozen promos over the last several years, but I've never bought any that had any warping to them at all, except for 2... a '58 Dodge with a very slight upward slope of the front side trim, and a '58 Pontiac with the same problem. All of the '58 Pontiac promos that I've seen have the same issue.

[mrknowetall]

From Wikipedia (in part)...

Though simply cast, promotional models were exquisitely detailed and proportioned, and by 1960, AMT became the main supplier of the pre-assembled model to American car companies. AMT worked most closely with Ford Motor Company and General Motors Corporation, but promo contracts among the model manufacturers seemed to alternate year to year (See Doty 2009a for a nice history of AMT's Ford Galaxie). Shapes of the vehicles were near perfect, though in the 1950s, cellulose acetate, the plastic of choice, was prone to serious warping. In 1960, AMT and some other manufacturers switched to styrene (the brand name being Cycolac) and by 1964, all of the major model car manufacturers had changed over to the new plastic. This solved the problem and styrene models 50 years later still maintain their form. 1961 was a key year for the switchover. For example some early 1961 Mercury Monterey two door promos were done in acetate while most for that year were done in the new non-warping Cycolac

Edited June 22, 2015 by mrknowetall

[mrknowetall]

https://en.wikipedia.org/wiki/Aluminum_Model_Toys

For those interested in the AMT story...

[Tom Geiger]

Here's some examples I own that I got in a collection. As you can see, there's no saving them. This is the reason I don't collect old promos. The '57 Plymouth body is so warped that the top has popped off. And the remainders don't have a single straight panel!

[John Goschke]

The warping and distortion in the acetate promo and friction models is the most obvious symptom of the real problem: shrinkage. The distortion occurs as different sections of the model shrink at different rates depending on the thickness of the plastic in a given area. That is why certain models have characteristic distortions, such as the Johan '59 Caddy "smile." Even if they can be straightened somewhat, they will still be undersize. Also, they will return to their original distorted state over time (though paint and plating slow that process.)

Acetate was used because of its gloss and opacity, which could more closely represent a painted surface. Cycolac replaced acetate on a widespead basis during production of the 1961 model year promos because it offered the same properties, without shrinking, though it can become brittle over time. There were a small number '55 T-bird promos molded in cycolac, but they are rarely seen.

[ranma]

Here's some examples I own that I got in a collection. As you can see, there's no saving them. This is the reason I don't collect old promos. The '57 Plymouth body is so warped that the top has popped off. And the remainders don't have a single straight panel!

In the case of the 59 impala two door In all fairness It could be saved. I have done this on a warped 60 impala 4 dr. Take it completely apart carefully useing a flexable grill lighter , directly heat the warped area. Carefull around the the window edge and push warped area back down keeping even pressure untill cooled will help reove the warpage to a less noticeable look. same could be done to the wagons roof But again useing exstream care when doing so.

[HotRodaSaurus]

Here's some examples I own that I got in a collection. As you can see, there's no saving them. This is the reason I don't collect old promos. The '57 Plymouth body is so warped that the top has popped off. And the remainders don't have a single straight panel!

OOOOH, I would love that wagon as a kit

[kruleworld]

My slightly warped Desoto Fireflyte didn't matter that it was warped, but i changed the chassis/interior with a 58 Belvedere.

[Longbox55]

Well, this saved me from asking the same question. I have a warped '57 Chevy wagon of unknown manufacture that's warped pretty bad. I was hoping I could straighten it out, if only to pop a mold off the body.

[3100 chevy]

I have an old un warped promo frame if anybody wants it

[Don Sikora II]

Well, this saved me from asking the same question. I have a warped '57 Chevy wagon of unknown manufacture that's warped pretty bad. I was hoping I could straighten it out, if only to pop a mold off the body.

That wagon was made by PMC. SMP made one too, but it had separate front and rear bumpers.

Long ago, I saw a demonstration on straightening out an old AMT Studebaker promo. The first step was making a mold of the warped body, making a casting of that, and then straightening out the resin copy of the warped body. Then a second mold was made of the straightened resin copy. Of course that means using twice as much rubber, but it's worth considering.

[Longbox55]

Thanks for the info Don. I was pretty sure it wasn't an SMP, but didn't know who else made promos of Chevrolets during that time period. I can't find any markings on this one, but I have not attempted to disassemble it. It does have a metal chassis plate, and the front axle has a gear on it, so I would think that it was offered as a friction variant as well. It does still have some of the silver paint on the bumpers. even as warped as it is, I can't really complain. Only gave $6 for it at the HMCA show about a year ago.

I'll keep the casting idea in mind. For right now, though, I'm going to give it nice home on my display shelf, warped or not.

[Casey]

The Banana Boat has arrived. 

[Ace-Garageguy]

Does this count?

[Snake45]

On ‎6‎/‎22‎/‎2015 at 10:39 AM, Bob Ellis said:

This makes sense. The wanted to make promo cars that kids could thrash around and looked nice out of the box.

And, apparently, most promos were doomed from birth to execution by firecracker, BB gun, .22 rifle, lighter fluid, etc. anyway....

(Or so I've heard. I've never deliberately destroyed a model of any kind in my life. Just ain't built that way.)

[Snake45]

5 hours ago, Casey said:

The Banana Boat has arrived. 

You could actually make a cool "T-shirt car" model out of that, if you could find some giant slicks! 

[martinfan5]

Oh gosh no, I wont willing buy anything model related part that is warped.

[ChrisBcritter]

On 7/7/2015 at 8:45 PM, Don Sikora II said:

Long ago, I saw a demonstration on straightening out an old AMT Studebaker promo. The first step was making a mold of the warped body, making a casting of that, and then straightening out the resin copy of the warped body. Then a second mold was made of the straightened resin copy. Of course that means using twice as much rubber, but it's worth considering.

Tom P. and I were talking about this lately; according to a conversation he had with Don Holthaus, this is exactly how the Modelhaus '56 Cadillac was created.

I wonder if a step could be skipped or minimized by putting wire in the mold as it's made and bending/stretching the mold into shape, then casting?

And just for nostalgia's sake, look at all these perfectly straight little Jo-Han '57 Plymouths and sigh for their future:

(source: the Hokey Ass Message Board's "Vintage Shots from Days Gone By" thread)

Edited March 10, 2018 by ChrisBcritter