Restoring a Top Hat

[Parazine]

First day of Lockdown!

And I've been dealing with bolts.....

Vintage Sevens (including Box Saloons and derivatives I seem to remember) have the front wings held on with coach bolts. On the Top Hat, these were the originals and were 3/16" dia, BSF threaded, which are unobtanium. The closest available is 5mm (3/16" is 4.76mm) but it's impossible to buy plain steel ones, suitable for paint; they all come BZP or sometimes blackened and often with printing, like this:

   

 However, it's possible to deal with the BZP finish, here's how:

Step 1, Deal with any surface printing. These are quite soft so a file will do the job. I also reduced the height of the square bit under the head.

   

   

Step 2 Mix some citric acid crystals (I used about 2 tbsp in a small jar) with hot water to dissolve them. Then pickle them for 1/2 hour or until they stop "fizzing" completely.

   

Step 3 Wash with plenty of cold, clean water but beware, they will rust easily! Now you have plain steel bolts, all ready for etch primer...

   

[David Stepney]

How resourceful!

[Tony Griffiths]

A super job!

[Howard Wright]

Hi Parazine

I’ve used these bolts on all three cars I’ve built/restored. I’ve never bothered with removing the BZP and so far not had a paint problem.  Perhaps I’ve been lucky in my choice of etch primer?

Cheers

Howard

[Parazine]

I used BZP, without primer on my Box Saloon, years ago and the paint fell off.
Used BZP on the Chummy with a yellow etch primer (can't remember the brand) a few years ago, seems mostly alright but the edges are showing bright plate now, probably enthusiastic polishing!
Thought this was the time to do the job properly!

[Renaud]

Hi Tim & everybody,
About chain hoist and RSJ I could'nt live without them. (To avoid polluting this post I open another post about RSJ and winches/hoists).

How could I have missed these posts? Now I had to read those 18 pages back!
I've subscribed now.
Splendid work Tim of course.
Thanks,
Renaud

[Hedd_Jones]

A flap wheel in the grinder, and 10seconds work would have removed both the plating and raised letters on the head. The BZP on the threads and underside of the head would have been beneficial over plain steel surely?

P.S I used 6mm stainless. And bedded them on Tigerseal

[Zetomagneto]

Run them up in the drill or lathe with emery, flap wheel would soon mis shape them.
6 mm is well oversize for chummy wingstays, mine are the little 3/16 BSF ones same as Parazine.

[Parazine]

On the way up!

I really love this stage of a floor up restoration, when the body finally starts to go back together and a car starts to emerge from the ruins that have been sitting around the garage. For months and months (years actually, I started this resto in 2018) I seem to have been working on bits of car, finishing one piece and moving on to the next without actually achieving anything but this week has made the difference and the Top Hat is back in town.

   

   

Wings went on with only cursory difficulty and the front end finally is aligned and straight after probably 90 years of being bent and misshapen. Changing the O/S cowhorn finally aligned everything at the front, even the bonnet fit is nearly right now. I think the body is very slightly twisted still but you have to know this to have a chance of seeing it and even I'm not sure!

I have three weeks left before I have to go back to work so the next priority job is glazing the remainder of the windows, then the new dashboard needs a lot of metalwork and paint.

[Ruairidh Dunford]

Yum!