Do I Keep Going or Back Off?

[jimbunyard]

Thermal coefficient of expansion is about the same for both aluminum and FRP and pretty high at about 25/degree C, so if you have a 0 or better degree freezer and some boiling water, the tube in the freezer and the bases in the water could very well work. Don't dick around though, I doubt you'd be able to get them apart if they stuck halfway and cooled/warmed in that position.

[rslifkin]

I agree with trying to cool the tube. Also, maybe see if you can find a way to try to rotate the flange piece on the tube. Twisting as you pull might help get it loose.

[Chotu]

I think some dimensions are in order here. End to end, as it stands, that thing is 5 feet tall. That is 3 inch aluminum, quarter inch wall. Those flanges are 8 inches across. The holes you see are 3/4 of an inch. This thing doesn’t fit in a freezer. LOL

This thing is made to take not only the compression from my cantilever dinghy davits, but also the tension from my Traveler up on the roof.

Since the expansion coefficients for aluminum and FRP are pretty similar, I don’t think I’m going to be able to get this back apart. Maybe it’s time to think about ways to press them further on, and if they fail, then it’s time for me to buy new materials. Goddamnit.

[jimbunyard]

2 pieces of 4" c channel 16" long, bolted onto the flanges at each end, 2 hydraulic jacks on each side with blocking to span the distance between flanges.

Or try slowly tensioning between the tree and the truck and tapping whilst tension is applied. The pulling force must be aligned with the axis of the tub; if canted to the axis you'll not likely
get it to budge.

Dry ice then, if your freezer is too small (haha).

[rslifkin]

You don't need to get it in a freezer to cool the aluminum. Fill a bag with ice to the limit of what will fit into the tube. Stuff it in the tube from the end, then point a hair dryer at the outer piece. That should be enough to produce some temperature difference to hopefully un-stick it.

[Palarran]

Man, I'm going with Back Off. How fast can you run backwards?

[Chotu]

Originally Posted by Palarran

Man, I'm going with Back Off. How fast can you run backwards?

No faster than my truck did. And that just broke a 3/4” dock line.

It’s not coming back off.

[MicHughV]

try some penetrating oil/lubricant, dribble some around the perimeter of the post where it enters the flange, may have to do it several times...let it soak overnight....the tightest grip....as you say....is right at the edge of the flange tube...then you have to find some way to immobilize the flange so that you can " twist" the post out. I'd even consider giving the edge of the flange a quick hit with a propane torch, prior to twisting the tube......it only needs a fraction to loosen...don't give up the ship here....a little forethought, some patience...and it will come out....

[Lodesman]

Even if you back it off, you're only likely to remove one flange, then you'll still be stuck with one on and nothing to grab it with. I say bolt the flange to a solid floor/deck/whatever - then wiggle the opposite end back and forth (side to side), using the leverage to work it out. Then flip it over and do the other end.

[MicHughV]

3/4" nylon has a breaking strength of around 12,500 lbs...if that broke...hmmmmm....

probably what happened...as you forced the post in, it caused a lot of friction...enough frictional heat to open the flange a micrometer or so, but once you let it sit, the flange cooled and contracted again to its normal shape...thereby locking the post in a death grip.

I don't see the post coming out without some heat applied to the flange.....any of the above suggestions to heat flange/cool tube would likely be worth a try..

[Chotu]

Originally Posted by MicHughV

3/4" nylon has a breaking strength of around 12,500 lbs...if that broke...hmmmmm....

probably what happened...as you forced the post in, it caused a lot of friction...enough frictional heat to open the flange a micrometer or so, but once you let it sit, the flange cooled and contracted again to its normal shape...thereby locking the post in a death grip.

I don't see the post coming out without some heat applied to the flange.....any of the above suggestions to heat flange/cool tube would likely be worth a try..

I don’t want to mess up the flange’s structural rating by heating it up. It’s fiberglass, already post cured.

I think instead of wasting the time, I’ll buy a new aluminum pipe section and see if they’ll get me new flanges or just pay my $120 for two more.

[jimbunyard]

Or you could just split the flange lengthwise with a saw, and put the cut to the 'back' when installing.

The forces are such that, when bolted to the floor/ceilng, the cut will have no effect on the post's strength.

If the cut worries you, glue it all togther when make the final assembly.

[rslifkin]

You don't have to fast heat the flange to damaging temperatures. Think about how warm it would get in the sun during the summer. Go for that temperature and try to cool the tube and you might have a shot.

[s/v Jedi]

Must be one of those weakly Ford trucks and fake Chinese dock line

[Chotu]

Originally Posted by s/v Jedi

Must be one of those weakly Ford trucks and fake Chinese dock line

What, do you need pictures of the fn rope?

Do I ever lie?????

You seem to participate in my threads, seem to want to offer advice which seems to be well intentioned, then you call me a liar??

It’s a Dodge RAM 3500 with a running start since the normal pull didn’t work and the tires just spun.

Tomorrow I’ll post a pic of the line just for you.

“ This is just an answer/comment; not interested in arguing or dealing with the trolls ”. You ARE the troll