West Peterson Posted April 14, 2008 Share Posted April 14, 2008 I have a perfect-condition 1930 dash knob (marbelized amber color) that is stuck to a cut-off and rusted shaft. I've tried soaking the whole thing in a jar of PB Blaster for more than two weeks, but still have not been able to remove the plastic knob. Apart from cutting the shaft at the end of the plastic, and drilling the rest out, is there anything else I can try?I've thought about soaking the whole thing in Coca-Cola (remembering my sixth-grade experiment of dropping a paper clip into a glass of the solution). Or, possibly a well salted solution... or even some type of acid. However, i do not want to ruin the knob, as it is so nice. Reproductions are no where near as nice. Link to comment Share on other sites More sharing options...
Restorer32 Posted April 14, 2008 Share Posted April 14, 2008 You might try heating up the remaining stub gradually until hot enough to pull out, then rethread or Helicoil the knob. Link to comment Share on other sites More sharing options...
Rusty_OToole Posted April 14, 2008 Share Posted April 14, 2008 Are you sure it is supposed to come off? Some knobs were molded onto the shaft. Link to comment Share on other sites More sharing options...
West Peterson Posted April 14, 2008 Author Share Posted April 14, 2008 No set screw. I'm pretty sure it's supposed to scew off, but I base this on knowing that the dash-light knob screws off. The knob I'm having trouble with is for either the choke or spark, so perhaps Tom or Rick can varify its attachment. Link to comment Share on other sites More sharing options...
mrpushbutton Posted April 14, 2008 Share Posted April 14, 2008 perhaps someone on the forum has a broken or runied knob they can dissect and tell you how it is on there? Link to comment Share on other sites More sharing options...
West Peterson Posted April 14, 2008 Author Share Posted April 14, 2008 I guess that weather it's screwed on or molded on, I'd like to know if there is any way of eating away the metal without harming the plastic (is it plastic?). Link to comment Share on other sites More sharing options...
Guest imported_Speedster Posted April 14, 2008 Share Posted April 14, 2008 The '29 choke and spark knobs are metal, not plastic, but they are threaded and screw on (normal right-hand thread). So, it does seem logical that '30s knobs were threaded also. Link to comment Share on other sites More sharing options...
Guest imported_Speedster Posted April 14, 2008 Share Posted April 14, 2008 In '30 there were also plastic knobs on the 2 gloveboxes. Could it be from one of those? The glovebox knobs may Not have been threaded on to shaft, since they would have a nut on inside? Link to comment Share on other sites More sharing options...
Rusty_OToole Posted April 14, 2008 Share Posted April 14, 2008 I was thinking about the headlight switch knobs used on many cars from the 40s 50s and 60s. Where the knob was molded onto the shaft, and the shaft pushed into the switch where it was held by a snap ring or otherwise locked in.Someone who did not know this might cut the shaft when he couldn't get the knob off.Have seen this type knob, screw on knob, and set screw knob all on the same dash board. Link to comment Share on other sites More sharing options...
34PackardRoadsta Posted April 14, 2008 Share Posted April 14, 2008 The choke and spark knobs on my 30 are plastic, and they look screwed on. I have not tried to take them off.You could try using galvanic corrosion to remove the metal. Place some salty water in a copper tub (3.5% table salt will work). If you don't have a copper tub than a plastic tub with a flat chunk of copper immersed in the water will do. Attach your metal post to the cathode of a 12V battery using a copper or stainless connector, and immerse in the tub. The tub (or chunk of copper) is then grounded to the anode of the battery. Current enters the electrolyte through your piece of metal, travels through the electrolyte, and goes to ground through the copper. 12V DC at very low amps will result in dissolution of 1/2 lb of metal in less than a day, so it shouldn't take long with your post. Just don't use tin or aluminum for the cathode (e.g. bucket). You will just end up with salty water all over the floor!Tom Link to comment Share on other sites More sharing options...
mrpushbutton Posted April 14, 2008 Share Posted April 14, 2008 Here are a couple of images to help this discussion along....... Link to comment Share on other sites More sharing options...
Guest imported_Speedster Posted April 14, 2008 Share Posted April 14, 2008 What is the knob for, on right side of dash above cigar-lighter? Is that the Heater-switch, dash-light switch or what? The '29 doesn't have a switch there.What ever it is, it has a plastic knob also. Link to comment Share on other sites More sharing options...
Tom M Posted April 14, 2008 Share Posted April 14, 2008 On my car that is the Map light. Link to comment Share on other sites More sharing options...
West Peterson Posted April 14, 2008 Author Share Posted April 14, 2008 Yes. Map light. Link to comment Share on other sites More sharing options...
Guest imported_Speedster Posted April 14, 2008 Share Posted April 14, 2008 Map-light! Man, How Modern can you Get! No Heater standard, but it HAS a Map-light! Link to comment Share on other sites More sharing options...
Tom M Posted April 14, 2008 Share Posted April 14, 2008 It is a neat thing. You pull is out in it lights up Link to comment Share on other sites More sharing options...
34PackardRoadsta Posted April 14, 2008 Share Posted April 14, 2008 Or in my case, sparks a bit! Or it did before I disconnected the wire! Link to comment Share on other sites More sharing options...
R W Burgess Posted April 14, 2008 Share Posted April 14, 2008 <div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body"> Or in my case, sparks a bit!</div></div>....Comes in handy for the Fourth of July Events! Wayne Link to comment Share on other sites More sharing options...
wheelerdds Posted February 19, 2019 Share Posted February 19, 2019 I am in the process of removing the dash on my 1930 726 and I can attest to the fact the the knobs on the choke and spark pulls are firmly attached. Fortunately I was able to unscrew them from the firewall. Any clues on removing the line connected to the back of the water temperature gauge? I have just about everything else pulled apart and it looks like there are three large screws on the inside the the dash on both sides holding it to the body. Anyone have any tips on this? Steve Link to comment Share on other sites More sharing options...
John_Mereness Posted February 20, 2019 Share Posted February 20, 2019 (edited) When I rechromed the window cranks on the 1935 Auburn, I was faced with what to do with getting the Bakelite knobs off - I asked a friend and he said it was a "piece of cake" - he said heat the shaft with a soldering iron and then pull. And he was right. Obviously, it would help to know how the knob was originally fitted - pressed on, threaded, or molded on. A little heat may help with the temperature gauge too ??? Edited February 20, 2019 by John_Mereness (see edit history) Link to comment Share on other sites More sharing options...
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