Replacement Screw Cap plans for 60-70's lamp upload

[Duane K]

Hello all, first time here.

I have an old lamp that was my grandma's and I'm a little sentimental about it.  It must be early 70's minimum because I remember it as a child.  I'm sure you all can probably identify it and that might help what I'm trying to do here.  A few years ago the cap cracked, it got cloudy and didn't work good anymore.  I'm in the process of trying to restore it, using the lava formula I found here.  I was about to say goodbye to it because I could not find a replacement cap.  Then I realized I could 3D scan the old cap, use that to build it in CAD, and have a replacement 3D printed!  So the cap should be back from the printer soon and hopefully it fits and the re-lava goes well.  I want to share the file used for the 3D print, it took about 10 hours and some pretty expensive equipment/software to reverse engineer.  The cap only cost $13 to print once I made the file.  I do want to make sure my replacement fits before I upload it.  I will also try to give updates on my overall success with the restore.  Here is a picture of the lamp so maybe someone can identify it.  Hard to tell in picture but it is gold-ish in color, and the cap screws onto the glass threads with an o-ring seal.

Buy it here https://www.shapeways.com/product/4TJ6AR66D/lava-cap-for-70-s-quot-...

[Dr. WHAT?!]

Excellent job! A lot of gooheads had to trash their old lamps bottle due to the always hard to find screw caps. I've been lookign into the 3D printing game and I never thought of a screw cap!! Just making mini nintendos for raspberry pi lol. Anyway great work, I posted your shapeways link in your original post so people see where to buy one!

[Duane K]

Thanks Dr.  Darn shame people have probably been pitching bottles for years, I was honestly a few seconds away myself before the 3D printer dawned on me.  There are some decent cheap scanners for cases and decorative stuff, but honestly from what I have seen it would be pretty hard to get a good scan on this cap without industrial metrology grade scanners.  The threads were tough, granted I was probably a little fussy but I'm used to working in microns.

[Duane K]

So I managed to make goo and have been running the lamp for a few days with the new cap from the local print shop.  It appears the plastic does not like the heat/pressure.  The top of it has domed up quite a bit.   Hopefully the shapeways cap I ordered will hold a little better.  It is listed as dishwasher safe and heatproof to 176F.  I'm not sure how hot the lamp gets but 176 is pretty hot.  It will be here Thursday and I'll update.  On a side note, as I was thinking my goo wasn't going to work I noticed the goo kits.  Wish I would have found that before.  By the time I bought materials I was out about as much money.  But once I got enough salt in the water it took off and is working great.  I actually had to cool it down and swap out some water for distilled to lessen the salt.  After being on for an extended time it stayed up top too long.

[Keith]

I don't know about Lava Lamp or Mathmos wax, but per a members conversation with a goo kits rep, temps over 130F can start to break down the wax.  Seems like 176F should be safe for normal use.

Duane K said:

So I managed to make goo and have been running the lamp for a few days with the new cap from the local print shop.  It appears the plastic does not like the heat/pressure.  The top of it has domed up quite a bit.   Hopefully the shapeways cap I ordered will hold a little better.  It is listed as dishwasher safe and heatproof to 176F.  I'm not sure how hot the lamp gets but 176 is pretty hot.  It will be here Thursday and I'll update.  On a side note, as I was thinking my goo wasn't going to work I noticed the goo kits.  Wish I would have found that before.  By the time I bought materials I was out about as much money.  But once I got enough salt in the water it took off and is working great.  I actually had to cool it down and swap out some water for distilled to lessen the salt.  After being on for an extended time it stayed up top too long.

[Duane K]

The Shapeways Cap came in!  It looks a lot better, there are no flaws burrs or voids like the other printer.  Some minor details like the radius on the threads and the lead in look a lot more like my CAD.  The other printer seemed to simplify it or reduce the resolution.  The surface is a little rough, this is the unpolished black (since I'm painting it).   But a light sanding with 400 will have it ready for paint.  I'll update on how it holds up.  FYI the pic has the O-Ring in.

[Kirk]

Looks great!  If it holds up, I'm ordering a few.  Thanks, Duane!

[SpartyGalRN]

That's awesome!

[Duane K]

I have a winner!  This lamp has been at temp for 24hrs with the new cap and no signs of distortion.  I got it up to temp and was making some slight adjustments to water density, measured the temp with a meat probe and it was 140F so well under 176F.  Put on the new shapeways cap and it has held.  The "other" cap was slightly domed after a couple hours and trashed after 10 hours.  Pic of the new cap painted and after 24hrs and pic of the old cap after 10hrs.  Paint process was:  Light sand with 200 grit.  Several light coats of Plastikote 467, wait 12 hrs.  Wet sand with 400 grit.  2 light coats Spaz Sticks Ultimate Black Backer, wait 3 hrs.  4-5 extremely light dustings of Spaz Sticks Ultimate Mirror Chrome, let dry 4+hrs.  Use a stick with some tape on the end to stick into the cap (only painted the outside).  Some good YouTube vids of the Spaz Sticks Chrome if your going that route (the one on pine wood derby car was good).  Probably would have turned out even better if it wasn't freezing outside.  I will give another update in about a week after a few on off cycles.

[Keith]

Wow, that looks great!  Honestly looks better (straighter, smoother) that some of my vintage screw-caps.  Love the color too!

[Duane K]

Thanks Keith.  So It's been a week and I have cycled it various hours every day. I left it on since Thursday, so 48 hours.  It is not warped at all.  I am so happy that this worked!!!  I also spoke to a designer in our machine shop who does a lot of 3D printing.  He made something to support a part for heat cycle test recently and confirmed what I suspected.  If the plastic does not warp at temp right away, it will hold for a long time.  I would enjoy knowing that what I did helped someone else, so if you print one please give feedback.  Also as I mentioned I could not use my original O-Ring (covered in glue).  The original should work, but I would like confirmation as it would save someone a few dollars.

[Jonas Clark-Elliott]

I have a couple of questions. First, how much did the Shapeways cap cost? Second, what formula are you using? That lamp ended up looking amazing, and I might like to try your formula.

[Duane K]

Thanks Jonas,  #1-The cap was $15 and it varies a little bit depending on the color chosen.  I marked it up $3 so it would be $18 if you got it from my "Store" on shapeways.  #2-I used the Perc and Wax formula I found on OozingGoo.  I think it looks and flows nice. I am a pretty good internet searcher and I didn't find anything about the goo kits until I had already gone down the Perc path.  It was a little time consuming, trial and error. I learned a few tricks that I could share.  I looked for a thread on the subject but didn't find one.  If you want more input on that maybe start a thread about it and send me a message and I will share my experience.  Unfortunately I have been having issues with the water getting cloudy and I think the salt content is too high so it is precipitating out of solution.  I might need to add raw wax to reduce the need for salt.  I have been too busy to mess with it lately and I might try a goo kit anyways.  If you feel like experimenting with the Perc maybe we can figure it out.