Refurbishing an outboard mounting bracket
Abadly corroded engine mounting bracket can be given a new lease of life with some simple preparation and painting techniques.
One of the reasons Avon inflatable dinghies have always been popular with boat owners is their adaptability and versatility. They were sold with lots of accessories including full boat canopies, bowdodgers and removable seats and floors. I even owned one which could be adapted to carry twin CO2 gas canisters so it could be inflated in 30 seconds to use as a liferaft.
Heavy duty rowlocks came as standard meaning the dinghies could obviously be rowed. An optional extra, though, for the round tail dinghies was the highly practical removable outboard bracket. This looks at first glance a slightly agricultural bit of kit but is actually an ingenious design which slots in four rubber beckets on the transom prior to full inflation of the aft tube.
So I was kicking myself when I sold my last Avon Redcrest for a bargain price complete with accessories including an outboard bracket. This was before I’d found and bought the new smaller Avon Redstart which would stow more easily on my 23ft boat. The newer, smaller dinghy was in very good condition and in my keenness to get it, I only realised later that it didn’t have an outboard bracket.
Fortunately a local dealer had some in stock including ones made of mild steel, stainless steel and GRP. Cheapest of the lot was a corroded mild steel one – which would clean up nicely.
1 This is the outboard bracket as I bought it. A saltwater environment is particularly pernicious to any form of mild steel which is left unmaintained. The level of corrosion is obvious here.
2 Originally these brackets had a special plastic-type coating and they can last for years until the coating gets damaged and is left unrepaired – leading to rust like this.
3 Because the corrosion had got inside the mounting pad channels I decided to remove the wooden block. These are riveted in so the easiest way to remove them is to drill off the heads.
4 With the rivet heads drilled off flush with the bracket, use a centre punch to drive the rivet shafts clear of the bracket. They might need a good thump.
5 Layers of rust on both sides are likely to jam the pad in between the channels. Using a piece of scrap wood to protect the pad, tap it out with a hammer.
6 The fastest way I’ve found to remove rust from a flat surface is to use an angle grinder and non-woven preparation wheel with integral backing pad.
7 For inside the channels I used the preparation wheel where I could and the rest was thoroughly scraped by hand and by wire brush.
8 Where the plastic coating was still intact a hot air gun was effective in softening it up before stripping it off with a scraper.
9 I then used 120-grit aluminium oxide paper by hand to remove any residues of the rust and the previous plastic coating.
10 Pitting caused by corrosion is harder to clean by hand and a wire brush in either a grinder or drill is really the best option.
11 I wiped the bracket down with solvent to remove any traces of dust. Wear gloves to stop grease from your hands contaminating the surface.
12 On bare steel it’s important to get a coating on fairly quickly. For this job Hammerite metal paint will be perfectly adequate – I gave the bracket two coats.
13 Before sanding and varnishing the wooden pad I filed away the rivets so they were flush with the surface. I then drilled out the centre of the rivets so I could re-use the same fixing holes.
14 When varnishing any component a good tip is to use existing fixing holes to support it or hang it while the varnish dries.
15 Rather than rivets I used 25mm round head stainless steel self-tapping screws to refit the pad to the bracket.