Is it ok to use stainless bolts with aluminium?

Adam wrote:
> Hi
>
> Thanks for replies to my earlier posting about securing my new fairleads. I
> have managed to gain access to underneath the relevant bit of the boat, so I
> can hopefully do a proper job viz a vis backing plates. Is it ok to use
> stainless nuts and bolt with aluminium - if not, what should I use?
>
> TIA

Yes, if you don't mind a semi-permanent connection

Use TEF-GEL (NOT Tuf-Gel) and the bolts won't become one
with the aluminum. If this is an aluminum backing pad and
not a cast aluminum fairlead you're talking about, then just
drill oversize holes.

Evan Gatehouse
 >> Stay informed about: Is it ok to use stainless bolts with aluminium? 

Steve writes:

> I might also suggest that when tapping threads in alum., use a oil
> especially for this purpose. You can get it at any outfit that
> speciallizes in machine shop supplies or from major bolt and screw
> distributor.

Also use a spiral tap for "stringy" materials, not a standard fluted tap.
 >> Stay informed about: Is it ok to use stainless bolts with aluminium? 

On Sun, 01 May 2005 19:52:27 -0700, Evan Gatehouse
wrote:

>Adam wrote:
>> Hi
>>
>> Thanks for replies to my earlier posting about securing my new fairleads. I
>> have managed to gain access to underneath the relevant bit of the boat, so I
>> can hopefully do a proper job viz a vis backing plates. Is it ok to use
>> stainless nuts and bolt with aluminium - if not, what should I use?
>>
>> TIA
>
>Yes, if you don't mind a semi-permanent connection
>
>Use TEF-GEL (NOT Tuf-Gel) and the bolts won't become one
>with the aluminum. If this is an aluminum backing pad and
>not a cast aluminum fairlead you're talking about, then just
> drill oversize holes.
>
FWIW:

I've retrofitted almost everything with 1/4" aluminum I've custom cut
myself (replacing original dished fender washers and "acorn nuts") and
that's what I do. Overdrilling the plates by, say, 1/8" allows an
easier fit below deck, too.

I seal the holes through the deck with epoxy, drill through that, coat
the bolts with sealant, coat the piece (say a cheek block) with
sealant on the bottom, pop in the bolts, get my wife to hold the SS
bolts with a screwdriver, and then I put a bead on the plate below,
put the plate on the bolts, and tighten LIGHTLY until I get sealant
ooze.

Then I lead the sealant set up for 24 hours to a week, depending on
what I'm doing. Occasionally this means covering the piece on deck.

I dog down the piece snugly and trim with a razor any excess.

The key parts are sealing the core with epoxy and coating the shaft of
the bolt with a very thin spiral bead. This leaves the head of the
bolt sitting in a little ring of bedding and prevents water getting
down the shaft, never mind into the core.

And the backing plate makes everything a lot stronger due to the
spreading of compression forces.

R.
 >> Stay informed about: Is it ok to use stainless bolts with aluminium? 

On Sun, 01 May 2005 20:53:57 +0000, Adam wrote:

> Hi
>
> Thanks for replies to my earlier posting about securing my new fairleads. I
> have managed to gain access to underneath the relevant bit of the boat, so I
> can hopefully do a proper job viz a vis backing plates. Is it ok to use
> stainless nuts and bolt with aluminium - if not, what should I use?
>
> TIA

I think it will be fine. If you use enough sealing compound to keep
moisture from getting through the deck or into the core (if applicable)
out, you will inevitably end up with enough compound on the SS hardware to
electrically insulate it from the aluminum.

In this thread, the process outlined by Rhys seems pretty thorough and
sound to me.

When I have done it, I just went ahead and tightened the hardware down
without waiting for the goo to cure. And I didn't use epoxy the way Rhys
does. If I could do it again, I would probably use something very like
Rhys's procedure.

--Mac
 >> Stay informed about: Is it ok to use stainless bolts with aluminium?