The misuse of rust converters. The Vactan myth.

[matty40s]

2 hours ago, cuthound said:

 

It even got rid of his ginger hair ?

I'm not sure we can export it to Canada.

[frangar]

So does the OP want to come back and reiterate what he said as it seems to have been well & truly debunked?  

[Murflynn]

Compair Holman (Comp Air, Holman Brothers  ??) is apparently a huge company.  Perhaps their public relations manager would like to comment on the fact that they (??) are apparently making false statements on a public forum about another company's products.

Edited January 20, 2020 by Murflynn

[Iain_S]

20 hours ago, sbainbridge said:

It's the water that is dangerous

https://www.fishersci.com/shop/msdsproxy?storeId=10652&productName=23751628

 

Too true!

https://www.dhmo.org/facts.html

[Machpoint005]

1 hour ago, Murflynn said:

Compair Holman (Comp Air, Holman Brothers  ??) is apparently a huge company.  Perhaps their public relations manager would like to comment on the fact that they (??) are apparently making false statements on a public forum about another company's products.

 

The successor company (Compair, no Holman) was sold in 2008 to Gardner Denver. I doubt they will care very much.

[Murflynn]

38 minutes ago, Machpoint005 said:

 

The successor company (Compair, no Holman) was sold in 2008 to Gardner Denver. I doubt they will care very much.

there is no limit to the glove puppet names that members might want to adopt - Sussex Royal comes to mind for example.

[blackrose]

I agree with the OP. I used vactan a few times before I knew better and I think it's crap and wouldn't use it again. Better to do the job properly. Get rid of the rust mechanically and use a decent primer or better still epoxy. I don't think there are many reputable professional boat painters who use vactan. It's mainly for the diy/amateur market.

[Machpoint005]

36 minutes ago, blackrose said:

It's mainly for the diy/amateur market.

 

Well, I'm an amateur d-i-y-er, so I'm happy with that.

[MtB]

1 hour ago, blackrose said:

I agree with the OP. I used vactan a few times before I knew better and I think it's crap and wouldn't use it again. Better to do the job properly. Get rid of the rust mechanically and use a decent primer or better still epoxy. I don't think there are many reputable professional boat painters who use vactan. It's mainly for the diy/amateur market.

 

You're obviously using it wrong somehow then. Works very well for me.

 

 

[Tony Brooks]

1 hour ago, blackrose said:

I agree with the OP. I used vactan a few times before I knew better and I think it's crap and wouldn't use it again. Better to do the job properly. Get rid of the rust mechanically and use a decent primer or better still epoxy. I don't think there are many reputable professional boat painters who use vactan. It's mainly for the diy/amateur market.

If that is the case then either they do not remove rust from pits or they spend hours grinding a mm of the plate or, more likely, those who care about the job use a far more aggressive "professional use only" type product. Having suffered a £5000 20 years go "budget" job where it micro-blistered and rust was showing in a very few years I can well believe some do nothing.

[BWM]

All rust treatments fall short of 100 percent but used with correct preparation they are an effective tool, i have done large areas with epoxy primer, Coovar rust converter and owatrol, all showed good results and surprisingly the owatrol seemed best: the only caveat being its slow drying time leaves it vulnerable, a brief shower became imprinted into it in the manner of a fossil and being an oil was impossible to rub down..

[blackrose]

1 hour ago, Tony Brooks said:

If that is the case then either they do not remove rust from pits or they spend hours grinding a mm of the plate or, more likely, those who care about the job use a far more aggressive "professional use only" type product. 

 

I worked on the insides of the hulls of two c1913 passenger steam boats and we made sure we did get the rust out of all the pits without taking any steel off and without using a needle gun. I do the same on my own boat. This is the inside of a locker that had water standing in it for a few years. I've since repainted it with several coats of epoxy. 

 

There's no rust in those pits (or very little). If you want to do steel prep properly you can so there's never any need to use vactan.

 

Some bits of that locker floor look like it's got some polished rust scale on it, but I went over it with a chipping hammer to make sure it was all off. That's just bare steel.

 

Edited January 21, 2020 by blackrose

[Murflynn]

59 minutes ago, Tony Brooks said:

 those who care about the job use a far more aggressive "professional use only" type product. 

Tony - can you suggest an example of such a product?

[BWM]

9 minutes ago, blackrose said:

 

I worked on the insides of the hulls of two c1913 passenger steam boats and we made sure we did get the rust out of all the pits without taking any steel off and without using a needle gun. I do the same on my own boat. This is the inside of a locker that had water standing in it for a few years. I've since repainted it with several coats of epoxy. 

 

There's no rust in those pits. If you want to do steel prep properly you can so there's never any need to use vactan.

 

Some bits of that locker floor look like it's got some polished rust scale on it, but I went over it with a chipping hammer to make sure it was all off. That's just bare steel.

 

Very well prepared but there will be some oxidizing that remains, even if it is microscopic. Epoxy will cope with that as long as the coating remains intact. 

[blackrose]

Just now, BWM said:

Very well prepared but there will be some oxidizing that remains, even if it is microscopic. Epoxy will cope with that as long as the coating remains intact. 

 

Yes the jotamastic I use is very surface tolerant and that level of prep is well within the recommended standard (ST 2.5 I believe?)

[Tony Brooks]

53 minutes ago, Murflynn said:

Tony - can you suggest an example of such a product?

The car body chaps at College rated something called Deoxydol (I think) but I don't see what is wrong with Vactan on a surface that has been prepped with a degree of diligence and used under the conditions stated by the makers. I do have some reservations about Fertan on horizontal surfaces but that is to do with washing all the dust and uncured product off.

[WotEver]

52 minutes ago, Tony Brooks said:

I don't see what is wrong with Vactan on a surface that has been prepped with a degree of diligence and used under the conditions stated by the makers. I do have some reservations about Fertan on horizontal surfaces but that is to do with washing all the dust and uncured product off.

^^^^^ This.
 

To my mind, washing off the residue simply introduces damp exactly where you don’t want it. 

[Boater Sam]

I have used neat Phosphoric with much success, its dangerous and Vactan seems to work in the same way and effectively.

[WotEver]

3 hours ago, Boater Sam said:

I have used neat Phosphoric with much success, its dangerous and Vactan seems to work in the same way and effectively.

I used two gallons of the stuff last year. I still have a (dirty) gallon left but dunno how effective it will still be. 

The difference with Vactan of course is that it also primes the metal.