too much pressure

doughboyshredder · Post by **doughboyshredder** » Sun Nov 14, 2010 5:00 pm

Damaged my press today. Not bad. Just bent one of the pieces of angle iron that supports the center vertical post. I wasn't paying attention and accidentally inflated to 110 psi!!!! No other damage.

Be careful people. I wasn't and could have been in a bad situation. Luckily my press is overbuilt and nobody got hurt.

richie · Post by **richie** » Sun Nov 14, 2010 5:24 pm

I've got a 2nd hand Norgren regulator/drier on my press, and have it limited to 60psi, longer term I intend to add an over pressure valve like Mike Magruder has on his MonkeyPress, thats prob the best and cheapest fiddleproof protection anyway. Glad to hear you didn't get any flying metal - can you post some pics please it might be good education for some younger guys who believe this can never happen. Cheers, Rich

doughboyshredder · Post by **doughboyshredder** » Sun Nov 14, 2010 5:34 pm

I definitely need to put an overpressure valve in.

skidesmond · Post by **skidesmond** » Sun Nov 14, 2010 5:56 pm

Wow that's a scary thought. Glad to hear there was no injuries.

When I re-pressed the skis for the Formica experiment I forgot to tighten the center support (5/8in steel rod). I started to inflate the hose and heard a piece of metal hit the floor. The flexing of the beam forced a 1inch lag bolt out of the wood beam. Took me a few minutes to figure it out until I saw a bolt on the floor and the lower metal brace hanging. I was probably at 25-30psi at the time.

I set my compressor at 40psi so it will maintain that as a max pressure on the out feed.

Can never be too careful!

falls · Post by **falls** » Sun Nov 14, 2010 5:56 pm

an overpressure valve is like a $2 modification
hang on maybe I should have one on my press too!

I have my air compressor output regulated to about 70PSI and then another regulator on the press at 50PSI, but probably a pop off valve would be a good safeguard. I might get a silencer too for deflating while I'm at it.

richie · Post by **richie** » Sun Nov 14, 2010 6:57 pm

$2? I will add one asap ! I have a $5 silencer on my plumbing already and its awesome, when I release the pressure it is a lot easier on the old ears, I also have a needle valve to control the inflation/deflation rate as its more adjustable than the good old ball valve. Never enough safety precautions with this much energy contained. Cheeers

COsurfer · Post by **COsurfer** » Sun Nov 14, 2010 7:30 pm

Good point dbs, I have found a few times I wasn't paying attention to the psi. I have a 90 psi safety valve but have never got that high, at least not yet!

twizzstyle · Post by **twizzstyle** » Sun Nov 14, 2010 8:01 pm

Woah... glad nothing happened man, that's scary.

I might get a safety valve for mine too, I hadn't even though of that. McMaster has them for like $7, you can request any PSI you want from 25 to 150psi in 5 psi increments. Search "pop safety valve"

I just did some modification to our press to make it a little more "roomy" since it's always been kind of cramped on the ends. In doing so I removed some key load path (didn't realize this until after). Now at 30psi I get noticeable deflection on the ends, dammit. Need to do some clever welding to get rid of it.

doughboyshredder · Post by **doughboyshredder** » Wed Nov 17, 2010 9:56 pm

Not sure what would have happened if I had laid a bead down the inside. Maybe a broken bolt? Yikes.

rockaukum · Post by **rockaukum** » Thu Nov 18, 2010 8:35 am

I see that alot of guys use angle iron for the mounting point of the supports. Would it be stronger if tubing was used and for added strength you could sleeve it for the pins?
ra

doughboyshredder · Post by **doughboyshredder** » Thu Nov 18, 2010 4:57 pm

rockaukum wrote:I see that alot of guys use angle iron for the mounting point of the supports. Would it be stronger if tubing was used and for added strength you could sleeve it for the pins?
ra

square tubing would be quite a bit stronger. Just not necessary for normal pressures. I mean, I let the airbags get to 110psi before I noticed that I hadn't set my regulator right. I am actually surprised that everything else held. I didn't think the bladders could take that much pressure.

rockaukum · Post by **rockaukum** » Thu Nov 18, 2010 7:45 pm

Got it.
Don't know if you have fire hose or not. It is tested while in service annually. Test pressure is 200psi for five minutes. Not that you will be going that high.
ra

doughboyshredder · Post by **doughboyshredder** » Thu Nov 18, 2010 7:57 pm

Yeah, it's fire hose. I got a whole roll of it from K2 when they closed up shop out on Vashon.

knightsofnii · Post by **knightsofnii** » Mon Nov 29, 2010 8:43 pm

Top and bottom cat bars? Or two bay press? Sorry for your mishap ive seen presses bust at similar pressures in a similar manner... like one busted weld and one bent beam... but the sound was like a gunshot and terrifying

doughboyshredder · Post by **doughboyshredder** » Mon Nov 29, 2010 10:20 pm

knightsofnii wrote:Top and bottom cat bars? Or two bay press? Sorry for your mishap ive seen presses bust at similar pressures in a similar manner... like one busted weld and one bent beam... but the sound was like a gunshot and terrifying

Bottom cat track separates two 1/4" thick steel plates. That's how I did my camber mold.

Adjustable bolts and bottom cat track allows the two sheets to flex independently of each other and still have the strength to withstand ridiculous amounts of pressure. Those are 3/4 x 1/2 square tube so essentially my bottom plate is 1 1/4" thick.

I found another bent bracket the other day. I'm pretty stoked that there was so little damage from such an overpressure.

And, that the board came out sick.

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