Refinishing old doors

[b_m_hart]

So, I've busted out the old heat gun, my fancy - shmancy respirator, and have stripped off 8 (?) layers of paint from the first of a bunch of doors in my place.  Now, the respirator is because of whatever nonsense is most likely in the paint I'm stripping off of 80ish year old doors.  I went through all of that, took a quick pass with the trusty sander, and the wood looks like it's going to be excellent to stain or put some other treatment on (other than paint).  The ETS 150/5 did a great job to show what looks to be beautiful wood after the initial paint stripping, but the real problem is the raised panel sections.

Any tips out there on what to do for the little nooks and crannies that have so many layers of paint on them?  I've tried using the heatgun and a wire brush, and it's somewhat successful, but not entirely.

 

[mwhafner]

I will be interested to hear if other members have better solutions.  The heat gun and wire brush has given me the best results.  It is still a painstaking process.

 

[tbellemare]

I seem to remember when TOH was here in Austin, they visited a shop that does old door and molding restoration all day, every day. If I remember correctly, they were scraping with a series of picks, knives, and awls after heating.

You'd kind of think they'd have come up with a better way...

Tom

 

[AlexThePalex]

If you really want to get every speck of paint off you can use either a Swiss pocket knife, the tip of blade has an excellent shape to get into all kinds of little corners, or you can use this neat little scraper by Sandvik.

http://www.jamestowndistributors.com/userportal/show_product.do?pid=3494&familyName=Bahco+%2F+Sandvik+Triangle+Scraper+625]

You can get all kinds of tiny blades for it to fit almost every shape and little corner there is.

Instead of a heat gun you can also use an aggressive paint remover acidic solvent (sorry don't know how you call that in America exactly). You apply it with a brush, let it soak for 10 minutes and then scrape it away. In my experience, it works better in tiny corners than a heat gun because the paint comes off all by itself and you don't need much force to remove the residue. This also doesn't leave nasty scratch marks on the wood. Don't let it touch your skin though.

 

[b_m_hart]

Cool, thanks for the helpful responses!  I'll post some pics tonight when I get home from work.  The problem isn't so much the panels themselves, there's a bit of trim where they meet the rest of the door, and the crease that it forms makes it very hard to dig the paint out, and I'm afraid I'll burn the door (so much that it can't be readily sanded out).

 

[mwhafner]

Speaking of heat guns . . . I was on a motorcycle trip a while back and spotted a restored Victorian home with a beautiful paint job.  I stopped at a gas station nearby and saw the homeowner out front so I struck up a conversation.  He and his wife stripped the entire house using a heat gun.  When they applied the new primer and paint, it would peel in some areas areas over the following months and that this typically occurred only after the first application of paint.  They did the restoration over several summers so when returning in the spring to resume work they would simply restrip the areas that peeled and reapply the the paint with no further peeling.  I'm contemplating using a heat gun to strip paint for an upcoming project. Has anyone else experienced this?

I have had similar issues, but I think my problem was the primer.  I don't remember which I had trouble with, but use Kilz Original, and haven't had an issue since. 

 

[nickao]

Kilz is made by Zinsser, at least I thought it was. Nope my bad,  Kilz is Masterchem industries.

I have used both Kilz and the Zinsser stuff never had a problem with any. Kilz is cheaper, but I do believe the Zinsser may be better overall.

http://www.kilz.com/pages/default.aspx?NavID=22

 

[mwhafner]

I have used the Zinsser BIN, and really liked it.  I wasn't crazy about the 123.

I also haven't been impressed with any of the other Kilz products, so I just stick with the Original.

 

[AlexThePalex]

When they applied the new primer and paint, it would peel in some areas areas over the following months and that this typically occurred only after the first application of paint.  They did the restoration over several summers so when returning in the spring to resume work they would simply restrip the areas that peeled and reapply the the paint with no further peeling.  I'm contemplating using a heat gun to strip paint for an upcoming project. Has anyone else experienced this?

The heat gun shouldn't be the problem, and neither should the primer, as someone suggested. When wood is properly prepared you should be able to stick anything on it. Some products are not as good as others, but even the worst of all should be able to hold for at least a year or so. When it only takes a couple of months, I'd say something else is happening.

There can be a couple of reasons why paint peels from wood and mostly it's because the wood isn't properly prepared.

Most peeling happens because the wood still has moisture in it. Wood really needs to be dry. Thoroughly dry, not just on the outside. If partially wet wood is painted the water will try to find a way out, is trapped by the paint, and will cause the paint to peel or the wood to rot.

Second reason is that the wood isn't cleaned good enough and there's still a greasy residue on it. This will also cause paint to peel very quickly.

Third reason is when the wood is slightly rotten on the outer layer. This can happen if it has been exposed for some time. If you paint over it now, you're basically painting over wood dust laying on top of the wood.

Another reason I can think of, especially with a heat gun, is that the wood is slightly charred. Normally you would scrape and sand that away after the heat treatment.

But the heat gun itself should have no effect on the paint job, as long as you treat the wood the right way after you've removed the paint.

Btw, you guys have Sikkens paint in America? I can't think of any better stuff than this.

 

[Woodenfish]

Geezies! Lead paint was banned in the US in 1978. Scraping, sanding and heat guns over 1100 degrees to remove 80 year old paint is a really bad idea fancy-shmancy respirator or not. Are there not professional strippers (get your mind out of the gutter) in your area who chemically remove that old paint with specialty chemicals designed for lead paint?

 

[John Langevin]

If you really want to get every speck of paint off you can use either a Swiss pocket knife, the tip of blade has an excellent shape to get into all kinds of little corners, or you can use this neat little scraper by Sandvik.

You can get all kinds of tiny blades for it to fit almost every shape and little corner there is.

Instead of a heat gun you can also use an aggressive paint remover acidic solvent (sorry don't know how you call that in America exactly). You apply it with a brush, let it soak for 10 minutes and then scrape it away. In my experience, it works better in tiny corners than a heat gun because the paint comes off all by itself and you don't need much force to remove the residue. This also doesn't leave nasty scratch marks on the wood. Don't let it touch your skin though.

This is basically what I use. First I dry scrape with with the small (one-handed) and larger (flat blade, two-hand) Sandviks to remove any loose or flaking paint and then apply the paint stripper (the type depends on whether it is paint or finish I am removing).

If you have a profile gage you can take that along with a cabinet scraper to a tool grinding shop and they will make a custom contoured scraper (useful for stock profiles). and then there is the handy-dandy LS130 sander setup.  I also use TADPOLE rubber sanding profiles with strip abrasives for hand sanding. I only use the heat gun as a last resort.

 

[b_m_hart]

I forgot to get pics last night, ugh... will work on getting at it tonight.  Part of the problem is that the original paint is on those doors, so there's all sorts of fun stuff there, topped off by a coat of a modern latex paint.  From what I saw of the paint strippers at the big box store the other day, they seem to be geared toward different types of paint - is this true, or is there something that will work pretty universally on all types of paint?

 

[AlexThePalex]

There are indeed quite some different types of paint stripper. With varying aggressiveness and greatly varying quality. Now I'm from The Netherlands so I'm not familiar with all the types of paint you exactly use in America, but here the paint comes in three main forms, Alkyd, Acrylic and Latex.

Alkyd and Acrylic paint have their own types of optimised paint stripper. About Latex I'm not so sure.

Latex is mostly used on walls, be it solid stone or gypsum plates. I never used an paint stripper for that and I doubt it will be fruitful. When you have latex on wood, which occasionally happens, it's best to scrape and sand it off since it won't bind very strongly with the wood and comes off easily.

Acrylic paint is paint based on the plastic acrylic, which is water soluble, as long as it hasn't dried. Mostly used for indoor wood, walls and outdoor walls. It is more difficult to sand this since the heat generated with sanding will burn it easily and make it curl and stick to the wood and fill up your sanding paper in no time. However, it is not very good resistant to chemicals so they made less aggressive paint strippers for this based on alcohol and acetone. They are not as strong as paint strippers meant for Alkyd paint, and also cheaper and less deteriorating for your health. They will not work on Alkyd paint.

Then Alkyd paint, based on Alkyd resin derived from oil. Solvable in White Spirit and similar solvents. This is the hard quality stuff used outdoors. There's loads of different strippers for this but the best and strongest are based on a chemical named Methylene chloride. This will also solve about any other type of paint there is, and your clothes and plastic and more, but not wood. Be sure not to go for the cheapest brand, because you can end up with stripper that hardly works. I know that from experience. Make sure you get a respectable brand.

Last thing I'd like to add is that there is a difference between very thin paint strippers and thick ones. Thin ones can be sprayed and are applied easier and more rapidly but their penetration is far less. Personally, I prefer the thick gel type of paint stripper, it's keeps working longer and that's better, especially if you need to remove multiple layers of paint.

But that said, it is possible you work in America with paint systems not familiar to me, maybe some other FOG member here can chime in, and you should also ask your paint store for good advise, they should know everything about it.
 

 

[Brice Burrell]

Well Alex has provided some pretty good info. My brother has done a ton paint stripping, I've seen him strip paint from numerous Victorian staircases, countless doors, windows and their trim. His method of choice is paint stripper, Bix tuff job, it's a semi-paste. He has an entire arsenal of scrappers, dental picks and brushes. There no question that it's unpleasant work for the inexperienced, it's time consuming and you're working with harsh chemicals. I'd pay pay to have the doors professionally stripped, it's not inexpensive but it sure beats playing with chemicals for days on end. If you do use a paint stripper stay away from the big box stores, go to a professional paint store or order a quality product online. Be sure to wear safety glasses and rubber gloves, my brother uses the long yellow gloves that a housewife might use to wash dishes.

As for exterior paint removal, this is where a heat gun comes into play, it's not safe to use paint stripper on vertical or overhead surfaces/moldings. Alex is right on with his thoughts on why paint fails. Most paint fails because of moisture in the wood. If the wood is wet it needs to dry for days before you can prime. I'd recommend a quality alkyd primer. Stay away from the Zinsser and Kilz, they have drying agents that can adversely effect it's durability. 

 

[b_m_hart]

There's exactly what I'm talking about, but it's pretty clear that you all have grasped what I was discussing.  One question I have is, if I continue to use the heat gun for this little bit, how far is too far (in terms of burning / abusing the wood)?

 

[Brice Burrell]

You'll likely burn the wood before you're able to remove the paint in the grooves, I'd try scrapping or paint stripper.

 

[John Langevin]

I don't know the name of the product but have heard old house restorers refer to it. It is a special "tape" that you apply to carved/milled mouldings and such, coat it with the accompanying stripping agent, let set and then peel it off. They say it works very well. I would try your local "professional" paint supplier, they should know what I am talking about (whereas I obviously don't ???).