Thread: The restoration of Wombat

Originally Posted by JDNSW

From an electrochemical point of view, stainless should not be used in contact with aluminium. If you do use it, use nylon washers and sleeves to prevent contact with aluminium. (Have a talk to any marine chandler about fixing stainless fittings to alloy masts)

Galvanised steel in contact with aluminium is preferable, but hard to get.

John

In a harsh marine application I agree, but in only occasionally fresh water damp conditions not an issue from the research I've done.

From the British Stainless Steel Association (talking about galvanic corrosion in marine applications) - 'Although aluminium is anodic to stainless steel, large relative surface areas of aluminium to stainless steel can be acceptable, dependant on local conditions.
Stainless steel fasteners in aluminium plates or sheets are normally considered safe, whereas aluminium rivets or bolts holding stainless steel parts together is an unwise combination, as there is a practical risk of corrosion.'

Given that I'll be using stainless fasteners in holding large areas of aluminium, I'm going to risk it - I don't intend to be sailing it around the bay with it.

They also look great.

Would I be correct in suggesting that these aluminium sheets are painted (thickly if you're like me) and that with a washer under the head of the bolt, there'll probably be minimal contact between the stainless and the ally anyway? Indeed, the hole would probably also have a layer of paint provided it was there before painting.

Bookmark this page so that when she falls apart in three years time, you can come back and find out why

Vibration & time and you soon have metal to metal contact.

BSF bolts are getting harder to come by, you have to go to a specialist supplier (read expensive). My local bolt place will get some sizes but you have to buy by the box quantity. HT bolts & nuts not available.
Most 'bright' bolts you buy now are zinc passivated, looks great but not for that long....

Galvanised or sheradised (dry galvanised) bolts would be the go but where to get them ???

I've never felt the need to go stainless, bolts & nuts (UNF) are so cheap that you could replace them if they get rusty in time.

Unless you want it exactly as per original you could use UNF for most applications where a nut & bolt are required. Anything into a tapped hole you may have to get the original bolts re-plated or live with the bolts as they are.


Colin

Forgive me father for I have sinned , as I too have used UNF bolts on Klonk, due to sudden shrinkage of the wallet syndrome.

I wanted 6 bolts to hold the fuel tank in, 3/8 x 1" plus nuts. Thought I'd keep it original and as our bolt shop keeps BSF and had some on the shelf ,I'd have them.

Was warned they were expensive but at $63 + gst for the 6 bolts , UNF it was.

Used this company when I lived in the UK B.S.F Bolts & Nuts
Shipping will add to the cost but for those applications where only BSF will do they can help.
Slotted screws are difficult to find, they tend to be Phillips head which is probably OK for a Series III but NQR for a Series I (but better than nothing).
BA is difficult to find (try Namrick) but metric sizes are close (as long as you're not going into a tapped hole) but screws are only available locally with Phillips heads again !

Some of the BSF bolts needed are are available from parts suppliers (like hub drive flange bolts).

Don't get Whitworth & BSF confused because the bolt heads are the same size.
Whitworth threaded bolts are easy to find & cheap to buy in Australia (look in Bunnings - but don't use them because they are poor quality). Just to confuse the issue there are some Whitworth bolts available with metric heads !

On the subject of originality....I was speaking to someone who restores old trucks. For a wooden flatbed on an early vehicle he is struggling to get slotted woodscrews. A 1920's vehicle with the tray covered in Phillips head screws just doesn't look right.......

Colin

Looks like you've been busy!!! A few things I picked up on.. 1.. Work light... Head torches are gold for this sort of work!! You'll forget you have it on, so buy plenty of batteries! We found some good Coleman ones for little money in K Mart.. 2. Throw the star dropper away!! Worst things to try and weld.. Find some 2mm of cuts from a sheet steel supplier!!, and 3.... Bolts.. You're not doing a concourse resto, so don't stress about finding UNF or BSF bolts (or whatever they were)... M6, M8, M10 and M12 are your friends.. Cad plated for all the structural things, and the bolts you've chopped, and stainless for the non structural, and where its going to be seen...

Originally Posted by Sitec

You're not doing a concourse resto, so don't stress about finding UNF or BSF bolts (or whatever they were)... M6, M8, M10 and M12 are your friends.. Cad plated for all the structural things, and the bolts you've chopped, and stainless for the non structural, and where its going to be seen...

Why metric when UNF are readily available at any bolt shop ?
I've removed poorly fitting metric bolts from a number of vehicles and replaced with UNF.
Cadmium plating has almost disappeared due to toxicity & environmental concerns, most are zinc passivated nowadays.


Colin

Originally Posted by gromit

Why metric when UNF are readily available at any bolt shop ?
I've removed poorly fitting metric bolts from a number of vehicles and replaced with UNF.
Cadmium plating has almost disappeared due to toxicity & environmental concerns, most are zinc passivated nowadays.


Colin

Yup, Zinc is what I meant. When I said 'Galv' in my head as I was writing it, I saw those thickly covered Shed Bolts, and thought Nah, gotta be cad. Yup, zinc is what I meant. I hear you re UNF, but so many places don't carry a good line.. but yes you are right. UNF would be ideal.