- – the best way I’ve found to remove NRVs is to put the wrench upright in a vise, put the stove over the wrench, then use strong downward force on the tank to keep the wrench head on the NRV head so it doesn’t skip off the end of the wrench. I demonstrate the technique in this section of one of my YouTube videos: https://youtu.be/2LKsxIYCTko?t=226
- – tighten the NRV just slightly/gently before trying to untighten. This may help to break the brass-to-brass bond if there is no NRV head washer present
- – if you chose to use penetrants… it will do no good at all to put the penetrating oils down the pump tube. The NRV is air and liquid tight sealed inside that pump tube. Instead, use a small brush and reach inside the tank through the fuel filler to apply penetrant to the outsides of the pump tube where it will run down the tube and get into the exposed threads of the NRV that are hanging out at the end of the threaded pump tube end block. That is where you want penetrating oils to assist.
Here’s a list of stove part suppliers that I’ve used or know about. As I think on it, I may add more, so check back frequently. This list is current as of June 2019. These suppliers tend to come and go in many cases. If I’ve listed your outfit and you don’t want to be listed just let me know in an email. If you find a dead link or if you know of a link I should add, please let me know by emailing: firstname.lastname@example.org and I’ll try to add, update or remove it as required as soon as possible. Thanks!
I have this great old Primus 100 stove that I’m trying to fettle. I’ve got the NRV loosened up, but it seems to be stuck in the bottom of the pump tube and won’t drop out of the tube. It’s hung up somehow. It wiggles around and is loose down there at the bottom of the pump tube. I wonder if there’s some gunk in the tank that’s hanging it up?
What can I do to get it free?
Stuck and perplexed
a. there can be a little burr of brass where the vent hole in the side of the NRV barrel was punched in the barrel. You can use your alligator forceps gripping the NRV head with an unscrewing motion (like you are unthreading the NRV) to “unscrew” the burr past the opening in the pump tube end plate. Do it with the pump tube opening facing toward the floor to allow gravity to assist you. Use a little 400 grit wet dry sandpaper or a small file to remove the burr once you’ve got it out so it doesn’t give you problems again.
b. the other problem comes about from using lead NRV head washers. The lead will expand outward when the NRV head is tightened down, sometimes into the opening for the NRV head threads. This can hang up the NRV. Alligator forceps should help you to get it out, again with that unscrewing motion. Consider to switching to HDPE (#2 plastic) NRV head washers. You can punch them from the lids of food containers, so they are cheap to make and they almost never cause these hang-up problems. They last forever, too.
With some vintage Optimus 8 stoves, there is no nut cast into the fuel feed pipe.
This makes disassembly to service the wick or unclog a fouled fuel line difficult. It is quite possible to break the fuel feed/vaporizer by trying to remove it through applying force to the spindle housing or the the small “stilt” that supports the burner. Then your stove is toast!
Here’s a simple do-it-yourself tool you can make. To remove the fuel feed/vaporizer body from the tank, make a block of wood. Drill a hole through it just the size of the fuel feed tube.
Then, cut it in half lengthwise. A thin-bladed saw such as a bandsaw works well for this so that you remove the least material. You could also use a Japanese pull saw if you don’t have machinery.
Clamp the block around the fuel feed tube in your bench vise or with a big clamp. Turn the tank counter-clockwise by hand to unscrew the vaporizer from the tank.
You can then service a clogged or charred wick, replace the wick or what have you. Enjoy the blue flames from your service work.