Bic pengun

[fenrir]

Viva la revolucion! By placing the original pen's nib into the muzzle, it can actually write! I went up to 400 psi 3 times, but then it started leaking

[jackssmirkingrevenge]

Nice effort! Solid rubber pistons are easy to make but at high pressures they do have their disadvantages due to the lack of rigidity.

[TrollingCluckster123]

400 psi in a plastic pen? That is not a good idea. Those pens are kind of brittle, so if one failed in your hand it would hurt a lot and also cause serious injury. Please use SCH 40 steel pipe for those pressures.

[mark.f]

He's using brass tubing, not the actual pen.

In regards to your other post, before you bring it up, there are a lot of things not rated for pressure that we use anyway... not always the right thing to do, but we're all adults capable of making a guided decision. For instance: a lot of the higher mixture hybrids we have on the sight are made from non-pressure rated parts, or parts par past their pressure rating.