Making New plastic window for gauges.

Hello,

i have a couple of Petromax 827 rapids, one came with out the plastic window for the gauge, and one with a plastic window that had become yellowish and bulged inward to the point where it interupts with the travel of the gauge hand.

So, how to fix ?

First get some suitable plastic, could be any kind as long as it is clear and transparent.

Then cut out a round piece with a hobby knife ( use the inner distance part from the gauge as a template)

Then place the plastic part inside the gauge cap, and hold it over a candle, just close enough to make it soft ( this procedure also clears up the plastic if it was somewhat cloudy from the start).

Not to close to the candle as this will cause bubbles inside the plastic, but just enough to make tha plastic clear up, and then gently press the inside of the plastic to make it bulge somewhat outwards, i know it can be warm, but we are used to that, right !

Now the new window is ready for use, and the now slightly bulged plastic piece is almost magnafying and it will not interfere with the gauge hand moving.



Good luck with your fettling !

Regards / Fred,

 

Looks good Fred, and relatively simple to do

 

If I remember well the plastic to use is the cover of a cd cover.
I guess most important is that it is fuel resistant.

 

Brilliant tip

 

Great insructions. I'm sure we have plenty of yellowed or clouded gauge windows here.
Only thing is, I find that most hard plastics which are transparent/clear are not very resistant to organic solvents, gasoline included.

 

Thanks guys, it does not have to be thick or hard plastics infact the original ones i have come by, (Primus 1930s and petromax 1930s ) are using very thin plastics, probably lucite, as they called it. these gauges has no pressure or fuel entering the area where the plastic sits, ( compared to level gauges ) the seal is on the other side of the lid. The yellowed plastic part shown for comparison is the original one from the Petromax, the one form the Primus lantern looked just the same, and they are actually thinner than the plastic i used. on new lanterns like the Santrax, they use something simmilar to CD cover material.
Fred.

 

Great idea! I have a plastic gage on my Px 828 that's clouded up, perhaps this method will work! Soon as the arthritis clears up a bit I will give it a try.

 

Here is a picture of the "Bundeswehr" (BW), matt grey version.
Marked Original Petromax as well as the Geniol type.
Thickness , measured at the rim is 1mm.
The half moon piece on top is not massive piece on the flat area but hollow and it curves down towards the rim.



Spoiler: notice the 4.
The plastic should be fuel resistant because we spoil fuel once in a while....

Here the Petromax D.R.P. version I have at hand.
Flat disc about 0,3mm thickness.



It would great to see more variations.

 

Yes, my DRP version its just the same thin style, but, newer ones just like the other style shown.

And most plastics are resistant or fuelproof as long as we talk keroseene.

 

Because I've got plenty Px 2827 made already 65 plastics for future…

 

, You are planning to collect many lanterns, and mainly Rapids !

 

I already have got 20 something Petromax 2827, mainly with damaged plastics, now, because is coronavirus and I have to spend lot of time at home, I made them plenty

 

A very good and informative post @Tive
Thank you for sharing.
Cheers
Pete

 

thank you for sharing your tip on replacing the window on gauges, I have a few lanterns with pressure gauge but no windows , they are a bit busted, if I couldn't find a replacement I would follow your lead and make them one way or another,
great fettling tip and directions and it all makes great reading.

 

Thank you guys ! for your nice comments, and good look with your fettling !

 

I do the same for flaslte lenses, easy and quick.

 

Ha. Thanks, @Tive!

I've just stumbled across this (again, most likely). I knew there was a thread here somewhere on plastic lenses for manometers. I shall make up a few.

Cheers

Tony