After much experimentation, frustration, thought, testing and retesting, I have finally decided on the final method to seal the main tube to the top plate.
Many failed experiments were tested before shipping, but the most reliable method at the time was used. The first 10 units had an o-ring in the channel, this worked on most of the units. The next series used sealant (mostly Teflon tape), but this was prone to working only if wrapped correctly and with the right number of turns. To make things more reliable and easier to maintain in the future, I wanted something both permanent and easy to replace.
Finally I have settled on a single O-Ring with Dash number 014. This O-Ring slips over the tube and sits in a groove just behind the threads. When tightened to the top plate (ideally just slightly in a vice to prevent un-threading when unlocking the lower ring) it makes a perfect seal. Some units have shipped with them in place as a black AFLAS o-ring, but as this is not a friction seal, it isn’t needed. The new part will be a red Silicone o-ring with a 70A durometer rating. This will give a better visual queue for replacement parts, and they will be for sale as a replacement part on our web store. As it’s not a wearing seal, I feel it will last a long time and spares will not be included by default with new Forges.
For any past customer, if you would like 2 free o-rings, I can send them for either postage cost, or ideally if you order some accessories. For accessory orders, my shipping calculation isn’t too great. I’m trying to improve this, but for now I’ve been just refunding excess postage to actual cost since most of the time I can re-use a padded envelope that I have for no cost to me.
In the future, I’m hoping to make a service manual that will detail how to break down any 2.1 Forge for long-term maintenance. I don’t expect this to be a necessary step, but I expect some would like to anyway on a yearly or every few years basis.