How I removed my Lewmar hatches using a heated wire

[sailah]

I was getting a tiny bit of leaking thru the caulking on my Lewmar Ocean hatches and decided it was time to remove and rebed.

Faced with how to remove the unknown sealant I heard about using a heated wire.

It just so happened that I had some of that wire when I made some heated motorcycle clothing.

The wire I used was Nichrome 26 AWG, bought for cheap on ebay a few years ago. I would probably use a little thicker wire if I had to do it again but I had it on hand.

nichrome | eBay

So the idea is you hook up a DC power supply to both ends of the wire, apply a voltage, the resistance in the wire is high and it heats up like a coil in your oven. The length of the wire matters, as does the voltage. I'm not an electrical engineer so I won't tell you exactly what to set your power supply at but I was using an ~18" long piece and running about 20V DC.

I used 2 box wrenches to hold the wire and alligator clips from my power supply to the wire.

My power supply is a "lab power supply" 5A, 30V. Handy for all sorts of testing on a boat and general usage. Mine goes to 30V

See similar here: 30V 5A DC Power Supply Adjustable Dual Digital Variable Precision Lab Grade 110V | eBay

Couple things to note:

• It'll only heat up the wire in between the leads
• Where the wire is in the sealant it'll cool off so use a gentle sawing motion
• The wire will probably break at least a few times, it did for me
• Use a wedge following behind the wire periodically to gently pry the hatch and allow the wire to cut vs getting pinched
• Drill a small pilot hole just under the hatch frame in hidden spot to allow wire to pass thru
• The higher the voltage, the hotter it will get
• You need about 4 hands to make it all work, unclip one of the wires if you need to stop, it'll burn something if you lay it down.

After some experimenting I was running about 20V, 3A thru the wire and it seemed like a good pace. I don't know how hot the wire got but it was hot enough to scorch the wood in a couple places, no big deal sanded it off. I think I did 2 hatches in about 30 minutes.

http://www.youtube.com/watch?v=EEG7Wn6En8M

[olepedersen]

Good information, I will use the setup on my boat thanks

[Suijin]

Try the stiff scrapers approach I mention in my refit thread. Faster, more control, less damage. If it works for 5200 it will work for anything.

[sailah]

Originally Posted by Suijin

Try the stiff scrapers approach I mention in my refit thread. Faster, more control, less damage. If it works for 5200 it will work for anything.

I tried that approach first but I wasn't getting anywhere. I tried razor blades, even a hacksaw. Couldn't get it started and it was cutting into the wood. I felt the forces were too high and I would damage something. 1/2 a dozen ways to skin a cat!!

[Pauls]

Another tool to add to the toolbox! Thanks for the post.

[UNCIVILIZED]

Filet knife. Though a garrote works too.

[sailah]

Originally Posted by UNCIVILIZED

Filet knife. Though a garrote works too.

I must have misplaced my garrote when I went into witness protection

[Suijin]

Originally Posted by UNCIVILIZED

Filet knife. Though a garrote works too.

Garrotes are so passé. The new thing around town in the bolito:

https://www.youtube.com/watch?v=U5J_Uh7rUCQ

[kentobin]

Thanks for the info.

I was removing some sinks in an old boat and what I assumed was sikaflex had finally turned into a compound more like 3M 5200. Ended up using a cheap knock off of a Fein multimaster tool with a scrapper blade. The blade works itself between the sink lip and the countertop and the motor really helps to cut through the sealant. Only issue I had is getting access all around the sink with the countertop still in place.

Setup also works well for removing sealant sticking to the deck after hardware removal.

[Bleemus]

Fein Multimaster with a toothed scraper blade makes quick work of hatches.

[alansmith]

Thanks for posting up. That was clever...

[jmschmidt]

Use a guitar string. The smallest, the E string I think. Put dowels on the ends for handles like a garrote.