Lift Hatch Gas Spring

[strace]

Have a '99 270 Sundancer. Manual states hatch struts are 26.3" extended x 16.1" compressed and 120 PSI. Maybe I'm dumb but every strut I located that would fit comes in different LBS, I understand thats the "amount" of force required to operate the strut but why is the manual listed as PSI. Conversion search for LBS to PSI might as well be in Spanish for me......guess my question is what LBS strut do I need. Thanks Much!!!!

 

[Lazy Daze]

Have a '99 270 Sundancer. Manual states hatch struts are 26.3" extended x 16.1" compressed and 120 PSI. Maybe I'm dumb but every strut I located that would fit comes in different LBS, I understand thats the "amount" of force required to operate the strut but why is the manual listed as PSI. Conversion search for LBS to PSI might as well be in Spanish for me......guess my question is what LBS strut do I need. Thanks Much!!!!

The "P" is PSI stands for pounds. It's basically the same thing (in the end). Just being listed two different ways.

 

[Creekwood]

Have a '99 270 Sundancer. Manual states hatch struts are 26.3" extended x 16.1" compressed and 120 PSI. Maybe I'm dumb but every strut I located that would fit comes in different LBS, I understand thats the "amount" of force required to operate the strut but why is the manual listed as PSI. Conversion search for LBS to PSI might as well be in Spanish for me......guess my question is what LBS strut do I need. Thanks Much!!!!

This should help:
https://www.iboats.com/shop/cabin-and-galley/boat-ventilation/gas-springs.html

 

[strace]

From a little bit of searching here it appears that 40 to 50 pounds of force is necessary for the engine hatch on my boat. But Lazy you're saying 120 lbs is the correct strut to purchase? Few other posts stated not to go over 50 due to hatch possibly popping open in rough water. I'm not doubting your response (you obviously possess much more knowledge than me per your profile) I just want to make sure I get the right ones and only have to play this game one time!!

It'll be a day or 2 before I'm back on the boat, I guess looking a the numbers on the current struts would help as well.

Thanks for the responses!!!

 

[Lazy Daze]

Yes. I have a 110lb gas spring here at the shop (and others, but this was the one I grabbed off the rack). I can compress it - but I need to put a good deal of my body weight on it (I'm 170lbs). There is NO WAY I was only putting 50 or 60lbs of pressure on it.

Keep in mind... while it may take you about 50lbs of force to start the lift the hatch (it should actually be less), you're lifting from the easiest spot... with the most "leverage". Where the spring attaches, there is much less mechanical advantage so the amount of lifting force needs to higher.

Here's how you can prove this to yourself. Get down in the bilge and have someone close the hatch on you with the springs disconnected. Push up on the forward edge of the hatch. Next, push up on the hatch where the springs attach. Be sure to take some food and water with you, just in case you get stuck...

 

[strace]

Yes. I have a 110lb gas spring here at the shop (and others, but this was the one I grabbed off the rack). I can compress it - but I need to put a good deal of my body weight on it (I'm 170lbs). There is NO WAY I was only putting 50 or 60lbs of pressure on it.

Keep in mind... while it may take you about 50lbs of force to start the lift the hatch (it should actually be less), you're lifting from the easiest spot... with the most "leverage". Where the spring attaches, there is much less mechanical advantage so the amount of lifting force needs to higher.

Here's how you can prove this to yourself. Get down in the bilge and have someone close the hatch on you with the springs disconnected. Push up on the forward edge of the hatch. Next, push up on the hatch where the springs attach. Be sure to take some food and water with you, just in case you get stuck...

Oh I'll take your word for it!! The hatch is quite heavy and I've never had to replace them so if it's 120......then 120 it is lol. Not interested in spending the night in the bilge either! Really appreciate the responses/information.