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Author Topic:   Blade Fuse vs. Glass Fuse
c level posted 01-06-2007 01:59 AM ET (US)   Profile for c level   Send Email to c level  
I cleaned up the wiring on my Montauk 17 today using contact cleaner, dielectric grease and a wire brush. It worked great and the electronics fire up. The only drawback was I broke off a tab one one of the fuse [holders]. It's not a big deal because there were extra empty fuse spots so I just rewired the line to an empty slot.

My main reason for doing this, besides maintainance, was so I knew what each wire was for. I am not the original owner of the boat. I was looking through the a catalog today and saw two very nice covered fuse blocks made by Blue Sea. One is for blade fuses and the other is for glass fuses.

Is there a big advantage and disadvantage of using blade fuses over glass fuses? I've only used glass fuses on my boat and the boat at work, so I thought maybe they are more reliable? Any suggestions?

Chuck Tribolet posted 01-06-2007 08:30 AM ET (US)     Profile for Chuck Tribolet  Send Email to Chuck Tribolet     
I've got the Blue Sea Systems glass fuse block, but they
didn't make the blade fuse block when I installed it. I'd
go with blades today. However, as long as you have empty
fuse spots, stick with what you have.


jimh posted 01-06-2007 09:37 AM ET (US)     Profile for jimh  Send Email to jimh     
Dielectric grease is a non-conductive grease. It is not intended to provide enhanced flow of electrical current, in fact, just the opposite: it impedes the flow of electrical current. It is often used in high-voltage situations like a spark plug to act as a sealant between the spark plug and its rubber boot, but as a non-conductor to prevent any electrical current from leaking to ground

To improve low-voltage electrical contacts, a conductive grease such as Burndy's Penetrox is used. This is commonly seen on battery terminals or other high-current, low-voltage connections, as well as in 120-Vac wiring at high current.

Chuck Tribolet posted 01-06-2007 11:33 AM ET (US)     Profile for Chuck Tribolet  Send Email to Chuck Tribolet     
The dielectric grease will get squeezed out, and a good
contact made. The grease will prevent corrosion and keep
the contact good.


c level posted 01-06-2007 01:35 PM ET (US)     Profile for c level  Send Email to c level     
Jim wouldn't it be better to use dielectric grease on fuse contact points? I know its not a conductor of electricity but it prevents corrosion around the contact points.

If you used a conductive grease and left any residue on the fuses, wouldn't it make a full connection and chance frying the electronics during a surge, especially if the grease ran?

Chuck Tribolet posted 01-06-2007 02:33 PM ET (US)     Profile for Chuck Tribolet  Send Email to Chuck Tribolet     
The fuses are there to protect the wiring, not the electronics
boat, and they protect from over current, not over voltage.


andygere posted 01-08-2007 12:32 PM ET (US)     Profile for andygere  Send Email to andygere     
The tabs on the glass fuses are bit more exposed, and more prone to corrosion. One of the fuse blocks on my Outrage seems to need a periodic cleaning, and should probably be replaced. The blade style contacts are less exposed, and I would think less prone to corrosion. They are also more durable, and I've broken more than one glass fuse pulling it out of a stick fuse block. Just make sure you keep a good assortment of blade fuses on hand, so you have one handy if it needs replacing.
jimh posted 01-08-2007 01:57 PM ET (US)     Profile for jimh  Send Email to jimh     
One advantage of a glass-type fuse (and by the way you can get them with a ceramic cartridge instead of glass but they're more expensive) is the ability to fashion an emergency replacement. All you need is a Kit-Kat Kandy bar. The procedure is:

1. Remove blown fuse from socket

2. Remove foil wrapper from Kit-Kat Kandy bar.

3. Roll layer or two of foil wrapper around the cartidge of the blown fuse.

4. Carefully install blown fuse with Kit-Kat foil wrapper back into fuse socket.

Presto! Temporary 25-Ampere fuse.

As ancillary benefit, you can enjoy the candy bar after the repair is done.

andygere posted 01-08-2007 04:08 PM ET (US)     Profile for andygere  Send Email to andygere     
Good point jimh, but I imagine a similar repair could be made with the Kit-Kat wrapper and a bit of matchbook on the blade type fuse. Not that I'd ever suggest bypassing circuit protection unless I were in grave danger.
seahorse posted 01-08-2007 06:08 PM ET (US)     Profile for seahorse  Send Email to seahorse     

Just a bit of blade fuse trivia info for y'all:

There are 2 types of blade fuses, the ATO and ATC series. The only difference is whether the fusable link is exposed to the air or sealed like the glass fuses are.

In a boat, especially in the transom area where gasoline fumes may accumulate, use the sealed ATC blade fuses for an extra margin of safety should one "blow".

It is easy to tell the difference, inspect the bottom of the fuse body by looking up from the blades. If the plastic housing has a small opening, that is an ATO (O for open) fuse, and if the housing is solid plastic, then it is an ATC (C for closed).

jflots posted 01-12-2007 01:55 PM ET (US)     Profile for jflots  Send Email to jflots     
I prefer circuit breakers.
SpeedBump posted 01-20-2007 02:04 PM ET (US)     Profile for SpeedBump  Send Email to SpeedBump     
I have used both blade and glass fuses. Initially I thought blades were better, easier to grab/replace than the glass and assumed more durable than glass. I found they corrode at the neck of the sealed plastic and have a tendency to break off at the neck of the tab.

This past season I installed a Blue Sea electrical panel that uses glass fuses for electrical distribution on my Nauset. The panel has a built in ejector to remove the fuse at each station and it has worked flawlessly. IT had lots of capacity for my needs and has a nice cover. My only concerns about the ejectors is they are thin plastic which overtime I am sure will get brittle and break. However I am sure for now and the foreseeable future it will service the boat well.

I would recommend the Blue Sea panel with glass fuses

TThompson posted 01-26-2007 10:55 AM ET (US)     Profile for TThompson  Send Email to TThompson     
I just ripped out the entire 12v system on my 17 and dropped on of these in.

The Fuses are located under the cover, inside a water tight compartment. (And the circuit lables are back light red when of, green when on and dark when the fuse is blown. Very Cool.)

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