Hull cleaning, weak caustic ok?

[Tim in Yorkshire]

The Sr4 has some minor soiling on the outside from being on a drying mooring. Is it ok to use a caustic solution to help scrub it off? The hull is gel coated and was waxed last season, the soiling rubs off with some effort when tested dry (it's on the trailer at the moment).

[matt h]

oxalic acid is the one to use for hull staining if thats what it is

[Tim in Yorkshire]

It's not really staining, more residue. Will weak caustic cause damage to the gel coat?

[Poly]

Originally Posted by Tim in Yorkshire

It's not really staining, more residue. Will weak caustic cause damage to the gel coat?

No you will be fine, traffic film remover is widely recommended and is highly caustic, keep it away from anything aluminium though.

[paddlers]

I got a bottle of cleaner from LBH online. It's shifted the road grime & orange peat residue from my hull a treat.

[Fender]

Get yourself a pot of Y10 ( oxalic acid in a gell form ) , paints on easily and just wash off with a hose

[Nos4r2]

Don't waste a small fortune on Y10, oxalic acid is available on Ebay for next to nothing in comparison, and you can turn it into a gel using wallpaper paste.

[Tim in Yorkshire]

Well after reading up a little more on caustic I decided to try something less agressive in the short term.

My dad recommended Persil Non-Bio, as he uses it to clean all sorts, from barbeques that have been left and grown their own ecosystem to burnt pans.

Anyway I had a go and magically with a light scrubbing brush and a bit of sponge work I did about half the hull in an hour last night, it seems to work a treat. The tricky bits are where the hull sits on the trailer, so I may have to try and move it a little. Hoping to launch it back on to its mooring this weekend after I finish the cleaning then re wax the hull.