Restoration of frame with black spots

[mwarriner]

Hi there,

I am currently attempting a nut and bolt restoration of an NC30 and one of the hardest things to restore to original seems to be the frame once the anodising on the extruded side pieces has failed and the dreaded black spots appear. Some people polish, paint or powercoat the frame but I wanted an "as original" finish.

The challenge is that the anodising of the extruded pieces would have been completed prior to the welding of the cast and plate extensions. Re-anodising is not an option as the welds and the cast parts will come out very different to the extruded brushed side pieces.

I thought I would share my efforts so please find below some photos of a small section that I attacked, bearing in mind that I have the whole of the extruded side pieces to do. I will be soda blasting the cast parts :)

So I took a deep breath and decided to attack it by:

1) remove the anodised finish by hand;
2) remove the pits where the black marks are
3) hand brush the aluminium
4) protect the bare aluminium with "something"

Frame before refinishing





Steps 1 & 2

Using a small dremel brass wire brush to open up the pits (they were deeper than I expected)



Using a wire brush to remove very hard anodised surface



Part 3

Hand brushing with 120 glass paper



Finally



I am planning on using Everbrite ProtectaClear coating (http://everbritecoatings.co.uk/protecti ... s-18-c.asp). I am also considering 2k lacquer but I sort of wanted to do every bit of the restoration myself and I don't have an air fed mask and don't fancy getting asthma (http://www.hse.gov.uk/mvr/bodyshop/isocyanates.htm)

Will report back once I have tried the ProtectaClear.

Thought it might be of interest to some.

Best,

Mike.

[Dynamohum]

Good work. Out of interest do you intend to clear coat the entire spar or the isolated area of repair only and does the clear coat you intend using require some sort of other prep like an etching primer?

[mwarriner]

Hi, I am not going to use a traditional clear coat but rather a type of finishing that is used in boatyards on fibreglass and aluminium to stop it degrading/oxidising. The coating I am going to use is called Protectaclear. Google that or see the link in my OP.

I will be finishing the frame next week so I will update all with progress as I make it/or fail at it

I have spoken to a number of paint shops and they are not keen to 2k clear lacquer it. Hence the ProtectaClear. The good news is that it is easily refinished if the coating fails over time.

Best,

Mike.

[alexko]

http://www.ebay.co.uk/itm/like/38069537 ... 122&ff19=0

I have the same issue on my frame.
Want to try this anodized looking aluminium out. Just have to wait for the weather to warm up.
I ordered 1 can but received 4 cans :-)
Will try it out on the inside of the frame to see how it comes up.
Was planning to finish in acrylic based clear lacquer, but might try this ProtectaClear