Angle Grinder for sanding on hull

[Murflynn]

again a little clarification.  I hope this is still up to date with latest industry norms:

 

Blackrose's cup brush is fitted to a male screw boss that is fitted to low speed angle sanding machines.

 

that Scotchbrite disc is fitted to a small (and high speed) angle grinder.

 

they are two apparently similar but actually entirely different types of machines.

[Mike Adams]

1 hour ago, Ballyeli said:

I've about a €2k budget to get this painted and back in water. 

Unless you can get someone the shotblast the bottom for this price, in my experience you will never clean it up well enough by hand to be any good for painting. Many of us over the years have cleaned up boats with wire brushes but if there is scale and pitting it only stops the problem for a short while. If the baseplate is 5mm I would just leave it and clean off and paint the sides. It will rust fastest along the waterline. Better to spend you time doing a really good job on the sides and accept in a few years(depending where it is on the water) its going to need a new baseplate. Those discs will only do a few square inches on that sort of  surface before they break up. Fine for surface rust on car bodywork but not much good on scale.

[Jon57]

On 16/09/2020 at 22:15, Ballyeli said:

I recently bought a 40ft narrow boat steel hull,

After getting it lifted and cleaned for a survey I discovered quite a lot of rust and a seam in the middle of the boat which needed filling and some pitting towards the front.

I got onto a welder and to save some time and money was hoping ( in favour of sand blasting) to use a grinder with a flat plate to sand down hull and prep it for welding.

Grinder is a dewalt battery 8000rpm and 180grit plate.....am I in any danger of eating through the steel and grinding it down too thin?

Hope they didn’t lift the boat on that hook !! ?will be blacking my boat this week and will be try with a combination of wire cup and wheel brushes of variety of sizes. Also got a Tercoo triple rotating rotary blaster to test out. The sales buff seems good. Will soon find out in the next few days.?

[WotEver]

2 hours ago, Jon57 said:

Also got a Tercoo triple rotating rotary blaster to test out. The sales buff seems good.

Do not. I’ll emphasise that, DO NOT push hard with the Tercoo.

 

Just rest it on the surface, be patient, wear ear defenders, and let the tool do the work.
 

If you push hard the tips will break. 

[TheBiscuits]

13 minutes ago, WotEver said:

Do not. I’ll emphasise that, DO NOT push hard with the Tercoo.

 

Just rest it on the surface, be patient, wear ear defenders, and let the tool do the work.
 

If you push hard the tips will break. 

 

Should we ask how you know this?

 

[Jon57]

36 minutes ago, WotEver said:

Do not. I’ll emphasise that, DO NOT push hard with the Tercoo.

 

Just rest it on the surface, be patient, wear ear defenders, and let the tool do the work.
 

If you push hard the tips will break. 

Got all that. Even using a variable speed drill. No more than 3000rpm is advisable to get best results and bit life.?

[WotEver]

3 hours ago, TheBiscuits said:

 

Should we ask how you know this?

 

Not saying...

[Ballyeli]

Cupbrushs are great but this really is a learning experience patience is pretty crucial this is gonna be a long week, battery tools were waste of time good shout on gene and mains grinder! 

Pitting is a bit crazy on front so have a welder doing that and the seam, that scotch brite disc was actually great but only after the scale was brushed down to a minimum definitely only as a finish!