How to loosen a bimini bolt?

Winkfish · Jan 20, 2011

Is it actually a nut and bolt that goes through the base bracket? Do you not have a very snug fitting wrench? You may need metric sizes.

jimoc · Jan 20, 2011

PB Blaster !!

kenn · Jan 20, 2011

RECESS said:
I have an aluminum bimini and I want to remove it to take off the sunbrella material to resew it. The bolt that holds the bimini to the base mounting bracket is super tight. I do not want to round out the flat tip head. Is there anything I can spray on the threads that will get into them and loosen the bolt? I could drill it out but I would like to keep the treads on the base mounting brackets intact. Any ideas?

To confirm, are you absolutely certain the bimini bow, pivot, base AND screw are all aluminum? (I have a dodger and the metalwork is all stainless, including hardware)

In your case, I would either remove the whole bracket to get the other bits apart, or I would just drill out the offending screw/bolt and replace it later.

Rick Webb · Jan 20, 2011

Someone has to Say it

With a Bimini Wrench

Seriously I'll second PB Blaster and add heat or cold if a source is available. In the Air Force we had cans of freon to spray on fastners of different sorts, doubt they still have those around. Maybe dry ice?.

Maine Sail · Jan 20, 2011

RECESS said:
No it is a bolt and the bimini base is threaded and acts as the nut. The only thing I have to work with is the flat head slot to try and back it out.

I will give the PB blaster a shot with a towel snugged around the fitting. I can just see PB blaster leaving an undesired finish to my gelcoat. The fitting is most likely stainless.

Beg, borrow or steal a cordless impact driver with a flat head screw bit in it and it will likely come right out...

jibes138 · Jan 20, 2011

Recess, If you don't care about the screw then after taking Maine Sail's advice you can file flats on either side of the screw then use vice grips to grab the head, it will likely come right out. I've used this method on screws with slots very effectively over the years. Also many of the screws for end fittings don't have a deep enough slot for the screwdriver to get a good grip. Shop around using that as a criteria on whether to buy or not. Use the vice grip method before drilling as drilling the stainless is no picnic and you will likely end up with a new bracket in the process.

jibes138 · Jan 20, 2011

Another trick, most home mechanics have a few sizes of screwdrivers. They use what they have and that might not be a good fit for the screw. You can get a whole set of bits at a hardware store for a reasonable price so getting the bit to exactly fit the slot will give you a better chance of removal without stripping out the slot , using a bit too small for the slot causes point contact at either end and starts plastically deforming the slot and then it just gets worse from there.
You can also use a small file to cut the slot deeper if it is too shallow so you can get a better grip, this is also a way to save a screw head that has already been damaged to get it out.

Bill Roosa · Jan 21, 2011

What Jibes138 said and....

once you have the right size screwdriver take a pair of vice grips and clamp them to the screwdriver. This gives you a handle and a lot more purchase and control. You can lean into the screwdriver to maintain head contact and really crank on the vicegrips.

Good luck

bljones · Jan 22, 2011

Maine Sail said:
Beg, borrow or steal a cordless impact driver with a flat head screw bit in it and it will likely come right out...

Or invest $10 and buy a manual impact driver.
I hate slotted fasteners and incompatible metals- it means you usually only get one chance to succeed. Having been here and done this, here is my usual course of action:
First, soak the fastener in question liberally with PB Blaster. Give it a spray daily for three days.
Second, pick up a tube of this stuff:
http://www.leevalley.com/en/hardware/page.aspx?p=32212&cat=3,41306,41329
when you only have one chance to unfasten locked up hardware, this stuff on the driver makes a difference.
Third, tap lightly on your impact driver. get the fastener moving.
Fourth, once the fastener starts to rotate, lubricate it again. rotate a half turn, and lubricate, another half turn, and lubricate, and it should back out with ease and no damage.