Homemade Full Face Mask

[skyjack]

So last night I was hanging out with a friend who works on boats all day. He was changing the filters on his 3M full face respirator like this one http://us.st11.yimg.com/store1.yimg.com/I/levineauto_1891_2301460. I put it on and thought to myself..."Wow, this is almost a dive mask!" It seals very well, all I'd really have to do is either add a regulator to where one of the filters goes and cover the other filter hole, or cover both filter holes and replace the one way exhale valve with a modified regulator. I don't think I'd have the nerve to use it anyplace other then in a pool, but it may be a fun project. He has his C-card and when I mentioned it thought I was nuts. I pointed out though that one could carry a spare mask and a high performance octopus. If the mask failed (assuming the mask regulator wasn't in free flow or something) one could just switch to the spare mask and octo. I guess the point to this project would be to A)See if it could be done B)Perhaps rig up a homemade communications system if the mask worked.

Anyone have any experience? Anyone see a super weak point in my plan? Thanks!

Rob

 

[james croft]

A lot of old gas masks were converted to underwater work in WW2 with surface supplied air. I would think it could be done by a handy DIY guy. The facemask is not flat and could cause distortion underwater. One-way valves would be needed to vent exhaust out with an oral nasal mask to avoid CO2 buildup. Need a noseblock for ear clearing as well. Seems like too much trouble for a second rate set up. I would recommend just buying a cheap Ocean Reef mask off Ebay if you want to dive a similar set up. They are a sort of jackleg gas mask adapted to diving. That is why there are so many sold on Ebay by folks who are trying to recoup some money back from them. I knew a guy who would give you an Ocean Reef for free but since it is a piece of state property it must be surplused. I'm not trying to discourage you as I have experimented with that type of stuff before, but it is not a good rig for diving.

 

[amascuba]

You have to think about the dead air space in the mask because it can lead to carbon dioxide poisoning.

Also, have you thought about how you are going to clear your ears with the mask?

 

[Storm]

You have to think about the dead air space in the mask because it can lead to carbon dioxide poisoning.

Also, have you thought about how you are going to clear your ears with the mask?

Wiggle the jaw, swallow...not everyone pinches and blows.

 

[cyclical]

Wiggle the jaw, swallow...not everyone pinches and blows.

If the ladies would only learn that technique us men would be much happier...



But seriously, a full face mask would be pretty cool as a DIY, I have a hell of a time equalizing as it is though.

 

[amascuba]

Wiggle the jaw, swallow...not everyone pinches and blows.

Most people don't have as easy of a time as you do. As I said though, it's something to take into consideration.

 

[skyjack]

Thanks for the great responses....as it so happens the mask has a built in sort of "mouth nose" cover so I don't think CO2 would be a huge issue. Usually I can clear without doing anything, I can just sort of make a clicking noisei n my throat and my eustacian tuebs open. It is very nice. The only time I have to pinch my nose is if I'm a little bit stuffy. Thanks again for all the input and I'll be sure to let you know if the project takes off....

 

[amascuba]

You might want to research the CO2 issue. The dead space in the mask can cause the issue. Having a mouth nose cover just means that their is probably a larger dead air space, which increased the risk.

 

[cyclical]

Not meaning to sound stupid, but what is the potential CO2 hazard about in dead air space?

 

[james croft]

It can lead to toxicity under increased pressure. Most full face masks use a oropharyngeal type mask over the nose/mouth area to minimize CO2 buildup in dead air spaces. There are one way valves to allow only fresh air to be used by the diver and for the CO2 not to be rebreathed by the diver. This would surely be a desired feature for a full face mask. I