Black paint on timber, I wonder?

[Bayliss]

Another little question, black paint has been daubed upon the exposed beams in our cottage (lovely :roll: ) In considering removal of same I am looking at the Soda Blaster option, it is said that this blasting medium can be used on delicate substrates to remove paint/gunk even from aluminium without damage to substrate. Has anybody here tried this method and with what results? Thank you.

 

[Flyfisher]

I've also heard of soda-blasting being a 'gentle' alternative to the usual sand/grit, but only in the context of removing paint from vehicles/parts before re-spraying. As you say, sounds ideal for aluminium castings but wood, even old oak, is far, far softer than aluminium and I'd be very concerned about doing more harm than good - unless you like the look of weather-beaten driftwood of course.

I understand the urge to seek out alternatives to the time-consuming chemical strippers or hot-air guns plus all the subsequent washing and cleaning, but I don't believe any sort of 'blasting' is an equivalent process; the end result will look completely different and, of course, there is no going back.

Fortunately, our better beams have not been painted but we also have plenty of beams that have been painted black. I'm afraid we took the lazy option and just decided to live with them.

 

[FamilyWiggs]

Flyfisher is right, in my book.

With beams I would avoid any type of blasting or pretty much any abrasive method (save foam backed scouring pads)

Strippers of Sudbury will have something to remove it:

http://www.stripperspaintremovers.com/I_want_to_remove.htm

 

[JoceAndChris]

Anything with the word "blaster" in it gives me the heebie jeebies too! I'd also say painstaking work with Klingstrip and a pressure washer/water sucker is the way to go, if you can really be bothered.

I'd agree with FF's approach, I don't think I'd have the patience to get it off. Are black beams so bad?

Then, there is also Gareth's latest extraordinary decorating idea to cover up these tiresome beams, a campaign room (I think) :

http://diffusive.files.wordpress.com/2009/10/schinkel-tent-room.jpg

I think there's a lot going for that - it looks very warm and cosy, a mood of exciting military adventure is evoked, and the deficiencies of the room are completely hidden.

 

[Bayliss]

Thank you for your interesting opinions, I cannot even begin to consider chemical treatments, hot air gun, maybe. Leave the black gunk as is, proberly. I am writing to the manufacturers of the soda blasting asking for their opinions on the matter, I shall post back.

 

[Penners]

I don't believe any sort of 'blasting' is an equivalent process....and, of course, there is no going back.

I would avoid any type of blasting

Anything with the word "blaster" in it gives me the heebie jeebies

Include my vote in this camp.

 

[MdB]

We are just going to paint our black beams white.

(a cop out I know but some of the beams are burnt so will look strange if we strip them.)

 

[Toby Newell]

I would not advise any kind of abrasive treatment. Either the abrasive will be too gentle (sanding) and not be able to remove the paint, or will be too aggressive (any form of blasting, no matter what the manufacturers/contractors say) and will remove a significant surface layer. If the wood is new and sound (no pest attack, checks/splits) and you plan on abrading finer (sanding) to take out the initial treatment marks then that is okay, but if old then some of the surface layer will undoubtedly crumble away, in particularly friable areas (with pest attack galleries for example, normally in all beams over 200 years old) large chunks of surface material may be removed. Either leave as is, re coat with another colour or remove by chemical means, you will have to finish up with a gentler abrasive means (sanding) as the chemical stripping process will not remove all of the paint, in fact you will never get all of the paint out of the interstices. Normally I would not recommend using a caustic poultice type stripper on oak as it stains the wood, but if your beams are 200 years old or more they should have a deep patination now of their own so this is not so problematical as it won't show up so much.

Like most things in life a job done properly takes more time and effort (and possibly money) but is worth it in the end, for if your beams are damaged by blasting, there is no going back. I have stripped and refinished a number of beams (including some for the Director of this site, Rob Taverndale) one customer had had the upstairs beams blasted in his 550 year old cottage before I arrived and when he saw what I achieved was very upset with the blasting, the wood was so friable, it just crumbled away and was very hard to coat with anything, even thinned out shellac with a squirrel hair brush, but never the less I coated and waxed them, they did look nice, except the gaping chasms where the friable wood had been blasted out of existence!

If all this seems too much then leaving them alone or a good wash, prep and repaint in a colour of your choosing may be more appropriate. I would not advocate getting a company in to strip them, unless you are particularly rich, as the time and care required to do a proper job (which is pretty messy) means anyone doing a sympathetic job will cost quite a bit. To be honest it is a very messy, tiring and quite unpleasant task the reward at the end being quite spectacular. If you are going to do it, do it yourselves and remember it is a labour of love.

Toby

 

[Toby Newell]

addendum...

If you apply a caustic based stripper, when removing I have found you can get excellent results by using an industrial pressure steamer, this works at pretty low pressure (barely enough to move a piece of paper a couple of meters away) but the bonus being super heated steam at the nozzle (120 celcius) this firstly reactivates the dried caustic stripper and simultaneously and gently removes the stripper/paint from the interstices, it uses relatively little water (around 2.5 litres an hour if you use it fairly constantly) so is easy to contain. I have got fantastic results with oak panels using this method (using solvent based stripper and boiling soda wash pre treatment) infact using this method I was able to remove so much stain (and retain all of the patination) that I did not need to oxalic acid bleach at the end of the process (normally required).

I use a Karcher pressure steamer which is just like the cheapo ones in Robert Dyas or on QVC but obviously a lot more efficient, they cost around £150 to £200. The one I have is the Kärcher SC1122.

Toby

 

[MdB]

ne customer had had the upstairs beams blasted in his 550 year old cottage before I arrived and when he saw what I achieved was very upset with the blasting, the wood was so friable, it just crumbled away and was very hard to coat with anything, even thinned out shellac with a squirrel hair brush, but never the less I coated and waxed them, they did look nice, except the gaping chasms where the friable wood had been blasted out of existence!

Have you some "what I can do" and "what blasting does" pictures? Removing blacking from beams is a very common question here and having some pics to explain why blasting is such a bad idea would be useful to point people at.

 

[FamilyWiggs]

Bayliss - when it comes to wood, Toby really really knows his onions (if you get my drift).

His comments on abrasion vs chemical means are spot on. It really is worth the effort, and once ruined a beam is ruined for ever.

 

[Bayliss]

Having arrived on this forum seeking good advise on the subject matter I would be an fool to then ignore that advise. I have decided to leave the beams as they are or maybe as one poster suggested paint with another colour. Thanks all.