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Modifications to 302 Bases to Prevent Thermoplastic Shells from Cracking

Started by Doug Rose, January 28, 2012, 04:42:52 PM

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Doug Rose

Here is a wonderful find in Western Electric's 302 lineage. The last metal 302 that I ever saw was 1/42, January 1942. This is clearly dated 7 31 41, July 31 1941.  Not sure what the 21790 in vermilion is. But it's Thermoplastic.

It is bittersweet as the shell has shrunk so it will not fit on the base. You can see how the sides have shrunk in and there are stress cracks like you see in a color 302 handset on the front and sides. They do not go through, but they are there. It does add to the character of the phone that otherwise is very shiny.

I added a IV41 5H dial, that fits no problem with the shrinkage. Odd that the 5H is dated quarter/year in 1941? There was no handset so  added one with 6/41 elements.

Doug



 
Kidphone

Dennis Markham

Very nice, Doug.  I especially like the dial card.  I've never seen a housing marked in that manner.  Is that housing marked with an H7 mounting code?

rdelius

I have seen several pre-early war plastic sets, all had similar numbers Serial numbers?.Never recorded them to see if they were the same.I do not remember if any one of them was not crackedRobby

Doug Rose

#3
Quote from: Dennis Markham on January 28, 2012, 04:55:29 PM
Very nice, Doug.  I especially like the dial card.  I've never seen a housing marked in that manner.  Is that housing marked with an H7 mounting code?
Dennis...its a H1....dial card is from Waltham MA just outside of Boston....Doug
Kidphone

McHeath

Wow!  Where do you always manage to find such prizes??  Never seen the like.

bingster

I've always wondered about that second number, too.  I've got one stamped "81441 26868."  Obviously, the first part is the date (Aug 14, 1941), but the second part?  I dunno.

http://www.classicrotaryphones.com/forum/index.php?topic=330.0 
= DARRIN =



Doug Rose

#6
Darrin.....at least mine didn't crack, but it still is really useless. Does your fit on the base with the crack

Anyone know if it is possible to cut the 1/4 inch ledge that goes around the metal base off. I have another 6/41 base that I'd be willing to use an an experiment to see if it would be worth it. It is just such a cool find, I hate to give up on it. Any ideas??...Doug
Kidphone

deedubya3800

We should create a list of these numbers with their dates and see if they're in order. My ivory 302 housing, dated 32342, has the number 60004 on it.

HarrySmith

I have heard of people cutting a small triangle shape piece from each corner of the base and bending the "ledge"  in slightly to increase clearance. I have not tried it but if you have a junk base why not? let us know the results!
Harry Smith
ATCA 4434
TCI

"There is no try,
there is only
do or do not"

Dennis Markham

#9
Doug, I know Chuck Hensley has mentioned grinding the corners of the base to allow the shrunken housings to fit over the base.  I have done the contrary (which he does not recommend) and ground out some of the plastic  on he inside edge, especially on the corners to relieve the shrinking.  I try and avoid grinding too much (using a Dremmel tool with a grinder bit), just enough to allow clearance.

I know there are two schools of thought on this situation.  On a non-black housing it is difficult to think of grinding away the plastic---for instance on something rare like your blue 302, but for black housings---which are plentiful----I've gone ahead and done that.  Often it doesn't take much.  Examine where it's rubbing against the base.  Sometimes it's on the sides rather than the corners.

Bill

I have not done anything like this, but I imagine you would want to drizzle a bit of thin superglue into the stress cracks to keep them from spreading.

Bill

Doug Rose

#11
Dennis.....Mark Scola used to do the same with the color 302s so they would not crack in the future. The more I look at mine, I don't think it was ever used. The shine is perfect, but all around top of the sides (make sense, the top area of the shell just above the sides) has small hair line cracks that do not go through and are not very deep. My guess these were caused by the shrinkage. They look more like tiny scratches than cracks. Some I can hit with a fingernail, most I cannot and glide over them.

This is a once in a lifetime find, so I don't want to damage it. I'd rather try the base as I have more than one with the same dates.  Any information about grinding down the edges of the lips of the base would be appreciated.

If you look at the sides of my shell, you can see it is schrinking inwards on the sides as well. I am hoping if I can get the edges off the base, I can get it working.

Any ideas are greatly appreciated.....Doug
Kidphone

Doug Rose

Quote from: deedubya3800 on January 29, 2012, 01:21:06 PM
We should create a list of these numbers with their dates and see if they're in order. My ivory 302 housing, dated 32342, has the number 60004 on it.
Darrin, does yours have metal hookswitch cover.

deedubya....I think yours has a painted metal cover, correct?.....thanks...Doug
Kidphone

bingster

 
Quote from: Doug Rose on January 29, 2012, 01:01:19 PM
Darrin.....at least mine didn't crack, but it still is really useless. Does your fit on the base with the crack
It does.  I've since closed the crack with superglue, and it still fits well (not too tight).  It does have the metal hookswitch cover on it.
= DARRIN =



sesjrs

I have started grinding down the corners on all of my 302 thermoplastic phones since they have serious shrinkage issues.  Here are some photos.  I still need to smooth the grind cut with a fine file.
Steve