18 replies to this topic

[Classic1275cc]

hi guys you know the self tapping screws that hold the grill on ect does anyone the aprox size of these I wont to order some stainless ones so they are waiting for me when I get home at the weekend end :)

 

 

[Classic1275cc]

orderd some of these http://www.building-...-8-box-100.html

[Jordie]

I dont think stainless is recormended.

 

Something about it reacting with the mild steel panel and causing it to rust quicker.

 

Bimetallic (galvanic) corrosion

Bimetallic (galvanic) corrosion may occur when dissimilar metals are in contact in a common electrolyte (e.g. rain, condensation etc.). If current flows between the two, the less noble metal (the anode) corrodes at a faster rate than would have occurred if the metals were not in contact.

 

 

Jordie

[HarrysMini]

If it was me, I'd use aluminium rivnuts as I personally don't like self tappers.

 

You can buy a gun and rivnuts for around £25, and they will cover a lot of jobs.

[sonikk4]

If it was me, I'd use aluminium rivnuts as I personally don't like self tappers.

 

You can buy a gun and rivnuts for around £25, and they will cover a lot of jobs.

 

Yet again you will get dissimilar metal corrosion from these as well. This is something i deal with on a everyday basis in my industry. If the hole for the rivnut is treated before hand ie painted and the rivnut itself has a anodised coating then you should be ok. But if these coating are not present then you will end up with problems further down the line.

 

Another thing you could use is a anchor nut especially the floating type. Now these will need to be riveted on and you will need small solids rivets normally Monel not aluminium. Or a monel cherry rivet. 

[Tamworthbay]

If it was me, I'd use aluminium rivnuts as I personally don't like self tappers.
 
You can buy a gun and rivnuts for around £25, and they will cover a lot of jobs.

 
Yet again you will get dissimilar metal corrosion from these as well. This is something i deal with on a everyday basis in my industry. If the hole for the rivnut is treated before hand ie painted and the rivnut itself has a anodised coating then you should be ok. But if these coating are not present then you will end up with problems further down the line.
 
Another thing you could use is a anchor nut especially the floating type. Now these will need to be riveted on and you will need small solids rivets normally Monel not aluminium. Or a monel cherry rivet.

I found this to my cost on a Robin Hood kit car I built many years ago. It had a mild steel chassis, stainless steel bodywork and used aluminium rivets. The instructions said to dip the rivets in grease but that didn't work. About a year after building it all the body panels were loose and vibrated. I had to replace all the rivets and do the job properly.

[Classic1275cc]

hmmmm interesting,  as a rule i smuther a bit of proper laqure about when i screw in a self tapper say for the grill which should help a bit, justt got pead of with steel self tappers because the other day i wanted to change a spot light bulb (5 min max job) and the flameing lenze screw was crumbly as a weetabix -__- want to avaid that proplem next tme  

[Ethel]

Galvanic corrosion will erode the less noble metal, which acts as the anode.

 

Stainless is more noble than mild steel. Mild steel is more noble than aluminium and zinc, hence zinc plated fasteners.

 

that lens screw will have been in a chrome plated rim, stainless would be a closer match there, just not in mild steel body panels. Simple solution, use nylon fasteners!

[HarrysMini]

I always paint any bare metal where a fastener would be used anyway. 

[Tamworthbay]

I always paint any bare metal where a fastener would be used anyway.

And then the self tapping action of a self tapper removes it when you screw it in. If it doesn't then the screw is way too loose.

[HarrysMini]

 

I always paint any bare metal where a fastener would be used anyway.

And then the self tapping action of a self tapper removes it when you screw it in. If it doesn't then the screw is way too loose.

 

That's true, and one of the reasons why I don't use self tappers.

[Classic1275cc]

good news i just got an email saying the stainless screws were out of stock and have been re-funded :L

[sonikk4]

Its down to doing a little bit more research really for finding the idle product to use. I use aerospace items whenever i can as i know their properties and where and where not they can be used. 

 

An awful lot comes down to the coatings on screws etc hence why you see a lot of anodised products to help prevent corrosion BUT if this coating gets damaged its back to square one again.

 

Mixing metals is not the end of the world but its down to how well the item is protected.

 

I know on my Clubby all of the mounting screws especially around the headlight area go into a small plastic nut that is clipped into the mounting bracket so no problems there but on a round nose this is not really doable.

[alex-95]

I would put rivnuts in, I put some M4's on the Ritz and is alot easyer to fit the grille.

[millermilla]

Grill screws on a mini, are they ever in there long enough to start corroding LOL?