Prepping surfaces for painting

[Alastair]

I have a lot of painting to do in this coming year, most of it on a fairly flat deck.

 

In the past I've used a wire wheel on an angle grinder to take off rust, loose paint and any other contaminants. Then (depending on weather) washed off all dust with clean water, allowed to try and used rags dampened with white spirit to wipe down before painting.

 

I've been using Rustoleum paints, thinned with white spirit.

 

Also done some railings by just wire brushing, wiping with dry rag and painting with hammerite.

 

The hammerite has adhered well, actually.

 

 

Suggestions for good technique welcome. I'm after rust-proofing steel as my priority, rather than mirror-smooth finishes. The boat is far too old and battered to achieve a mirror finish.

 

[Ex- Member]

I have a lot of painting to do in this coming year, most of it on a fairly flat deck.

 

In the past I've used a wire wheel on an angle grinder to take off rust, loose paint and any other contaminants. Then (depending on weather) washed off all dust with clean water, allowed to try and used rags dampened with white spirit to wipe down before painting.

 

I've been using Rustoleum paints, thinned with white spirit.

 

Also done some railings by just wire brushing, wiping with dry rag and painting with hammerite.

 

The hammerite has adhered well, actually.

 

 

Suggestions for good technique welcome. I'm after rust-proofing steel as my priority, rather than mirror-smooth finishes. The boat is far too old and battered to achieve a mirror finish.

 

 

At the end of the day as long as you remove rust and loose paint and take the shine off of any existing paint then you should achieve good adhesion and prevent or at least dramatically slow down further corrosion. Also de-greasing with spirit as you've mentioned is also essential.

 

Other than what you'r doing only grinding or shot blasting would be any kind of improvement.

 

You could also choose to use a rust inhibitor as well prior to painting. I believe Rustolium have these built in. Hammerite as well supposedly. Many people make the mistake with Hammerite of only applying one coat. You should do 2 at minimum and I would do 3 on a boat.

 

Rustolium also do a paint designed even to paint direct on rust, might be worth looking up the data on that.

 

TBH though you're not doing much wrong IMO

[JDR]

Using a shaggy roller (if that's the right word) to apply paint is a great way to hide surface imperfections on an area like deck where finish isn't critical.

[smileypete]

For large horizontal areas of thick flaky paint it's hard to beat a scabbler from a hire shop.

 

If the metal is fairly flat, then a zirconium resin fibre disc in different grades, plus backing pad in a grinder should linish it nicely and do a better job than a wire wheel. Bit safer too as no loose wires to fling out. There are also flap wheels more suited to small corners and fiddly bits.

 

Can sometimes pick them up quite cheaply on Ebay, abtec stores is a good seller and may do the even harder wearing ceramic ones too. For rusty pits a proprietary rust remover like Bilt Hamber should do well, or make your own from phosphoric acid.

 

Don't know if a scabbled surface is good enough to paint on or whether it's worth linishing too, maybe one of the pro painters can comment.

 

cheers, Pete.

~smpt~

[pquinn]

For large horizontal areas of thick flaky paint it's hard to beat a scabbler from a hire shop.

 

If the metal is fairly flat, then a zirconium resin fibre disc in different grades, plus backing pad in a grinder should linish it nicely and do a better job than a wire wheel. Bit safer too as no loose wires to fling out. There are also flap wheels more suited to small corners and fiddly bits.

 

Can sometimes pick them up quite cheaply on Ebay, abtec stores is a good seller and may do the even harder wearing ceramic ones too. For rusty pits a proprietary rust remover like Bilt Hamber should do well, or make your own from phosphoric acid.

 

Don't know if a scabbled surface is good enough to paint on or whether it's worth linishing too, maybe one of the pro painters can comment.

 

cheers, Pete.

~smpt~

how would you go about making your own?.the fertan i bought was ridiculously expensive with only one dealer in Ireland. paul

[Alastair]

Lots of rust pits, unfortunately. Many of them old and with lots of old paint in. Some newer.

 

I've not been impressed with phosphoric acid treatments. Paint adherence is poor over them. Metal paint like rustoleum or hammerite seem to do a better job of sealing and protecting surfaces.

 

In your experience, is a scabbler quicker than wire brushing with angle grinder? Even doing a small area with the grinder takes a long time.

[smileypete]

Lots of rust pits, unfortunately. Many of them old and with lots of old paint in. Some newer.

 

I've not been impressed with phosphoric acid treatments. Paint adherence is poor over them. Metal paint like rustoleum or hammerite seem to do a better job of sealing and protecting surfaces.

 

In your experience, is a scabbler quicker than wire brushing with angle grinder? Even doing a small area with the grinder takes a long time.

 

Haven't used a scabbler but there's a few threads here on using them, looks promising enough to be worth a try. Needle gun could work too for smaller less accessible areas.

 

What treatment was used? Ones like Vactan, Fertan just convert the rust to a thick black compound and not remove it, they're based on some sort of tannic acid I believe, their name gives a clue. Ones based on phosphoric acid should remove the rust completely, leaving a greyish black surface, good for rusty tools too.

 

As for making a phosphoric based rust remover there's info out there on the web, easiest way would be to thicken it with something to stop it running off the surface, though for small areas it might just be easier to buy some.

 

With hammerite it might be a bit brittle to knocks and foot traffic, not usually a problem with metal railings.

 

cheers, Pete.

~smpt~