Painting over stripped doors

Joined
6 Sep 2011
Messages
2
Reaction score
0
Location
Newcastle upon Tyne
Country
United Kingdom
I've had some doors 'dip 'n' stripped' as the state of the paintwork was terrible. I want to paint them again but I am finding that some areas of the wood must still hold the chemical in them (caustic soda I think) because the paint just reacts and cakes on these areas. They don't look or feel damp still (they've been back in the house three weeks). Any advice please on how to deal with this? - could it be the paint I have chosen - Roseal's knot sealer, primer and undercoat all in one. It's water based - would an oil based primer be better? Thanks
 
Sponsored Links
Dipped doors should be neutralised before attempting to repaint them. This is generally done by the company that does the dipping but if there is still some residue, vinegar usually does the job well if mixed as a mild solution with water. Once dry use cold water and a rag to rinse the areas again.

You will need to remove the paint from the affected areas to do this before repainting. If the Ronseal doesn't work then, an oil based primer may be a better bet. If the problem still persists you could even try alkali resistant primer but this is not usually used for wood as it is designed to stop salt problems from within masonry substrates.
 
With regard to wood Alkali Resistant Primers are more associated with the sealing of fire damaged timber yet they can be used in your situation, in fact Leyland Trade Alkali Resistant wall primer is recommended for both masonry and wood. However they will offer no protection against sealing resinous bleed so the use of knotting solutions also needs to be taken into account.

Dec
 
Thanks MisterHelpful and the TheDec for both bits of advice. Sounds like I should start with the vinegar!

How strong / weak does the solution need to be, and how much should I be using, ie does it need to be really sloshed on, or is it more a case of 'squeezed out rag'?

So far I have only tried painting one side of one door, so on that one I know the problem areas. On the still bare wood, I suppose I will have to do the whole door as I don't know where problems might lurk. Will it be necessary to change the rag and the vinegar mix often (to avoid spreading residue I wash off to other areas of the door) - or am I thinking about this too much now?!)
 
Sponsored Links
As said, the doors should have been neutralised and rinsed as part of the dipping process so there should only be trace amounts of the chemicals left. The ratio of vinegar to water could be a case of trial and error but I would suggest trying 1 part vinegar to 4 parts water, applying it with lightly rung out rag (fairly wet but not dripping). Once done, you can rinse with clean cold water in a similar fashion and hopefully the problem will be solved.
You will probably find that the moisture will cause the grain of the wood to raise a little and, when dry, some light sanding with fine paper will be necessary to smooth the surface .

I'm by no means an authority on this subject but I had a similar situation a number of years back and this method worked well. Before going to these lengths though, it could well be worth contacting the stripping company for their advice, just in case the chemicals they have used are different and vinegar won't act as a neutraliser, meaning all the effort is in vain.

PS.
The water shouldn't need changing regurlarly as the vinegar should neutralise the caustic soda on contact.
 
If your paint system as you say cakes on application after a caustic dip indicates that there is indeed a high alkali factor, I myself can't see how a good result good be achieved with a vinegar wash albiet household, white, cider, or balsamic.

Dec
 
What you need is a neutraliser, you could as said contact the people who dipped the doors or you could google strip away neutraliser. This product comes complete with litmus paper so you can determine the correct ph of the doors.

Dec
 
Dec,

Vinegar is an acid which will help neutralise tha alkaline base of caustic soda and is commonly used in these circumstances. It's pretty basic chemistry but as I have said, the strength of the solution will be trial and error and double checking with the strippers would be a wise move.
 
Dec,

Vinegar is an acid which will help neutralise tha alkaline base of caustic soda and is commonly used in these circumstances. It's pretty basic chemistry but as I have said, the strength of the solution will be trial and error and double checking with the strippers would be a wise move.

Yes I appreciate that, yet it's the trial and error that is my concern, by using the correct products the op will be able to determine both whether it is safe to apply his paint system, and whether there is a need to apply a alkali resisting primer.
 
...it's the trial and error that is my concern, by using the correct products the op will be able to determine both whether it is safe to apply his paint system, and whether there is a need to apply a alkali resisting primer.

True enough, and I agree that it could take a long time to 'get it right'.
I think the best way forward at first is for KatMatt to check with the stripping co. to avoid wasting time and effort on unnecessary/unproductive work.
 
At the onset it would indeed be the best approach, they should have the knowledge to at least point the op in the right direction.

Dec
 

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.


Are you a trade or supplier? You can create your listing free at DIYnot Local

 
Sponsored Links
Back
Top