Brass vs. Bronze screws

I use brass screws a lot in canoes and kayaks but only for freshwater. They are weak so I just put steel screws in first then replace them with brass.

Works for me.

 

Well I suppose we could debate the alloys from now on but I do have white brass ports on my 13 metre Rasmussen. This boat has a history of many ocean going trips and there is no corrosion nor pitting in the unfinished white brass. The boat came out of the same boatyard that built the Bismark.
Now, I DO predrill and countersink for brass. That gives me about 3/16 of hard enamel with urethane on the heads. And doing this, you will never strip one out. I do use phillips headed screws.
At this point it just appears that like everything else, everyone has a preference based upon their own experience.
As my dad used to say, "Wouldnt the earth be a dull place if everyone was just alike?"
Regards,
Sam

 

As I understand the corrosion process an electrolytic cell is formed between two dissimilar metals connected by an electrolytic solution such as sea water. In the absence of a dissimilar metal (as in my otherwise all-wood canoes) or a connection through an electrolyte (e.g., above waterline components such as ports) this presumably does not happen so only other, slower corrosion processes apply.

Is this more or less correct?

If so then brass is OK for some boat-related applications but not others. I (think that I) learned a lot from this thread.

 

kayaker;

Hit the nail on the head there or the screw as the case is!!!
Very good!
I do some projects which require specific metals and alloys so I am somewhat familiar with these processes. My Rasmussen is a steel hull and the original teak was applied with steel screws. The screws outlasted the teak!! Over
60 years of serious ocean going exposure.
I would reinterate my choice is for brass (In wood boatbuilding) is primarily due to the sanding problems. As I stated, I refuse to use wood filler on top of the countersunk screws. So in getting everything faired for paints, hitting a screw with the sander is just no problem and by about the third coat of a good urethane enamel all the phillips heads dissappear and are forever sealed in the paint.
Regards,
Sam

 

Brand new to boat building.
I am building a plywood boat and will be putting a fibre glass coating with epoxy over the wood. My question is, will stainless steel screws be better protected under the glass and therefore nit an issue with longevity?

Sorry if this is a basic question

 

Can I just throw a question in here rather than start a new thread. I am brand new to boat building and woodworking but am going to try and build the Glen-L Sissy Do.

I will need screws and read a lot about the issues with brass and stainless steel but if I were to coat the outside with fibre glass will i have the same issue or is my creation safe?

Thanks people

 

Welcome to the forum.

I'm sure that you read this thread from its original post. Lots of valuable information given by some very well informed sources.

Search this forum for threads relating to encapsulation.

Will screws be the primary structural condition? Or are they "temporary" until the glasswork cures?

I would use bronze in the first case; SS in the latter.

Good luck