Drilling holes in aluminium hulls - Correctly!

[bootyinblue]

Guys, I am thinking of installing some extra rod holders in my boat along with the bait board. I know that once you take the paint off the hull, it can be susceptible to all sorts of nasty reactions. What is the correct way to treat the raw edges prior to installing the rod holders.

I had some ski hooks fitted before I picked up the boat originally and now there are pain blisters and bubbling around then. Been back to dealer who fitted/sold the rig and have not heard back from him after 4 emails, so they are about to go on the 'Lets rid them' thread.

But for the moment, just need advice on how to treat and cover the raw edges.

[mackmauler]

its more to do with what comes in contact with the raw edges i think, if its a dissimilar metal thatll cause it.

[bootyinblue]

Oohh ok, maybe that is where fibrous washers come in to it, or I know there is some sort of paint style application you can add. So I would be pretty sweet as there will only be plastic touching the raw edges of the alloy.

[faulked]

its more the stainless screws or worst still gall screws alloy rivets are ok but hard to use big heavy ones strong enough for a rod holder

[AZZA]

Hi the product I was told about is Duralac to treat holes I haven't picked up any yet but I supose any good chandlery would stock it.

[bootyinblue]

Thats the stuff... Thanks AZZA and Karma to you as soon as I have some to give!

[Gazza]

Seal it with selastic thats what we do @ work

Gaz

[chubbstar]

AZZA wrote:

Hi the product I was told about is Duralac to treat holes I haven't picked up any yet but I supose any good chandlery would stock it.

I have that stuff, Cost me $30 for a tube:blink: .A tip, if you're using a steal brakets that run a couple of inches place rubber or something like that between the two metals. Use the Duralac in holes and small areas.

Jayson

[Burko]

Sikaflex is the stuff you want, comes either white or black. pretty strong stuff too. I have used it to mount my bilge pump to the bottom of my hull (inside dopey) and also as a temporary but now permanant fix for my side mount rod holders.

[bootyinblue]

Cheers for that guys,

Now let me think, Duralac $34.95, Sikaflex $14.95 or liquid nails left over from my gates $Free.... Which one do you think I will use Ellicat?

[ellicat]

Go one of the first two. I reckon you might need to keep some spare liquid nails for future repairs:laugh:

[bootyinblue]

Its not even bloody finished yet, so I cant even contemplating repairs yet. Broke severeal palings getting them off the rails originally so I am about 6 palings short of a fence ;-)

Just need it to get dark now as there is a new housing estate at the end of the street......

[AZZA]

Just rember that liquid nails will over time dry to be hard and brittle so depending on what you are sealing might no be the best . I use polyurathane on my boat have not had any problems it is the same stuff they use in cold rooms .

[bootyinblue]

Yea thanks Azza, I am not that much of a slap up merchant. Was having a dig at Brian as I said that with a hammer and liquids nails I can fix most things around the house. I will look at Sikaflex or silicone I think.

[AZZA]

Was pretty sure you were joking , but posted just incase:laugh: Also a trick when drilling alli is to spray a small amount of WD40 or such onto hole saw this will stop the teeth of hole saw clogging up and go slow.

[Gazza]

Silicone works a treat and I believe most tinnies if not all are made from marine grade ally

and your right Mackie it's called electrolisis

I'd have to check but I think it is ferrous metals vs ally

stainless does not have that effect

Gaz

[faulked]

hey gazza look up the galvanic chart it should show you just how many metals are on it and how they react to each other
/>http://www.metal-mart.com/Guides/Galvanic.htm

[bootyinblue]

AZZA wrote:

Also a trick when drilling alli is to spray a small amount of WD40 or such onto hole saw this will stop the teeth of hole saw clogging up and go slow.

Better still me and Gaz used Lemon Fresh dishawashing liquid. Lubes well, has a nice lemon scent and blows great bubbles!

Will post some pics shortly of the finished project, and put all the doubters out of their misery.

[Fishing Freddy]

Kero is a good lubricant when drilling ally, and a slow speed drill is better than a fast one as it won't heat up as quick and clog up the teeth in the hole saw. hope all goes well Ken

[bigtez]

One of the biggest problems we have found is poor paint application. You would be surprised how many manufacturers don't prep the alluminium before they paint it. The other issue to watch out for is creating too much heat when you are making the holes causing the paint to delaminate and allow water underneath it. Add some duralac or sikaflex to the raw edges and in the screw holes. As long as you can stop most of the saltwater getting in between the dissimilar metals then you will minimise corrosion.

[Gazza]

bootyinblue wrote:

AZZA wrote:

Also a trick when drilling alli is to spray a small amount of WD40 or such onto hole saw this will stop the teeth of hole saw clogging up and go slow.

Better still me and Gaz used Lemon Fresh dishawashing liquid. Lubes well, has a nice lemon scent and blows great bubbles!

Will post some pics shortly of the finished project, and put all the doubters out of their misery.

It does TOO :woohoo: lmao