stripping old doors

[petenchez]

G'day,

Just discovered this great forum after a bit of a late Friday web surf.

We are renovating a 1926 bungalow in Perth with loads Jarrah including solid 40mm thick doors. The doors have about 6 layers of paint on them, and we have have been sucessful with the heat gun & paint scraper up until now, but have one that has been painted with an unusual green undercoat that will not budge. Allof the layers above came off with the heat gun & scraper, but not this gunk. Have tried sanding, but paper gets clogged very quickly. Have tried "citri strip" - not much good, and am a bit skeptical about stripers anyway due to the mess.

We have seen & heard a bit about caustic diping (and maybe some others methods that may not be caustic). Can anyone out there advise if these methods are any good? Will it ruin the door or cause it to warp, shrink, or for subsequent finishes to peel off? Do you know of anyone in Perth who offers this type of "dip & strip" type service (assuming you think the method is appropriate)?

Happy wordworking...

Pete 'n' Cherie

[Grue]

I had a lot of doors stripped in a caustic bath some time ago in Sydney. The guy that did them neutralised the caustic with a mild acid and they turned out really good.
If you don't neutralise the caustic, it will damage the door.
I did some smaller work and used caustic drain cleaner as the stripping agent and neutralised the job with vinegar. That works ok but for big jobs like doors the professionals work out cheaper, just make sure neutralising is done too.
Grue

[ubeaut]

Before going to the extreme and expensive caustic bath have a go with a good paint stripper. That would be one without citrus in it.

It's not all that messy and will be a lot better for the doors than the caustic, which has a side effect of breaking down glue joints in timber. It can also discolour some tannin rich timbers of which jarrah is one.

Paint the stripper on in a heavy coat then cover with cling wrap or similar to exclude the air. Leave it sit until the paint has softened then scrape it off. If it is a "water clean up" stripper wash the surface down with hot soapy water after the scraping is done. If not wash it down with metho and steel wool.

If there are a number of coats you may need to do this more than once.

If you are a bit of a clutz, use rubber gloves, eye protection and protective clothing as it burns skin.

Hope this is of some help.

Cheers - Neil

[Shane Watson]

And if you know the right people you can get hold of aviation paint stripper... Damn this stuff lifts damn anything, not to mention skin.. hehehe...

[Grue]

Its a synthetic hydraulic oil "skydrol"
won't hurt your hands but you'll be a sorry lad if you have the slightest skerrick on your hands when you go to the loo! Ouch is not good enough and one can't swear on this board!

[petenchez]

Thanks hepas for the advice. We'll grab some "real" paint stripper & give that a go as it is only one door,the other 12 have been OK.

Thanks also for the advice on the issues wuth Casutic; We'd rather not risk damaging the joinery as these doors are very very heavy.

Cheers,

Pete & Cherie

[derekcohen]

Pete and Cherie

I just want to reinforce the warning against dipping your doors, as mentioned early on. Several years ago I had a few old pine four-panel poors dipped (taking the easy way out, what with all those mouldings), and it was a disaster. I think the guy who did them was a bit dodgy, and I didn't know better at the time. They looked fine for a month or so, but they were probably not neutralised properly. As a result they developed a chaulkish residue, which oozed up for years. The joints never really were the same as the drying process (after being dunked and soaked - for how long?) was not done well and there was much expansion/contraction. In the end I had to junk these wonderful old doors. So sad.

I used a heavy duty chemical stripper (unfortunately I do not recall the name, but the aviation stripper suggestion sounds good) on a finish that was designed to defend against chemicals. This was a green painted surface on an 100-year old jarrah chemical lab bench I rescued from the University of WA. So it can be done.

At this moment I am stripping old varnishes and treatments from bentwood chairs. I am using Citristrip and this works well for this type of finish. I wouldn't recommend it if your needs were more heavy duty.

Regards from another Perthite

Derek

[journeyman Mick]

Pete & Cherie,
Have to agree wholeheartedly with the warnings regarding caustic baths. I've had a fair bit of work over the years repairing furniture and joinery that has been stripped in caustic baths. Neutralising afterwards only prevents further damage, lots of damage has already been done. The weight of the item itself, or the weight of the person sitting on it, in the case of a chair will tend to pull the joints apart over time.
Being safety conscious (well most of the time, there have been a few falls of roofs )I would recommend that even if you aren't a klutz you wear PPE (personal protective equipment) when using chemical strippers.

Mick

[mkcl]

Hi Pete/Cherie,

A while ago, I was stripping the paint off some timber and discovered an undercoat that sounds almost exactly like what you've run into. (Anybody know what it might be?) I was using a belt sander, and as soon as I got through to the undercoat, the belt acquired a nice thick coating of green gunk and became almost useless.

What I found was that the gunk was quite soft while warm, but hardened up somewhat once it cooled. So I switched off the belt sander for a minute, chipped off the gunk, and then resumed sanding. Definitely took quite a while to finish the job, but it was quicker than a drive to the hardware store and back. At the end of the process, I just chucked the belt, which cost all of $1 (definitely cheaper than any paint stripper I know of).

Only a few problems with this method:
1) A belt with gunk stuck on it leaves bad scratches. Once the last trace of undercoat was gone, I went back and sanded it again with new belts to get a smooth surface.

2) This only works on a flat surface. If your door is ornate, I guess you're stuck with using a paint stripper (although you might be able to minimise the amount you use if you sand the large flat surfaces first).

Michael.

[BrianT]

Greetings Petenchez,

You may like to check out a product called PEEL AWAY which is made under license by Haymes Paints in Victoria.
www.haymespaint.com.au

I have often used a suede shoe brush to get into the fiddly bits.

A pro painter stripper mentioned than in pre-historical times thinned down tar was often used as an original coat and is the proverbial pain in the...... to strip.

Apart from that, the advice from Neil is the go.

Cheers

Brian @ Burra

[TroyfromPerth]

Has anyone else used lye before to strip paint? Lye is just caustic soda. You can buy 500g tubs of it for about $4 at coles or bunnings. - similar approach to what Grue suggested with using drain cleaner. The good thing is that its alot higher in concentration (~96% neat caustic soda) than the drain cleaner that you can buy. Ive just mixed it with water before and it seemed to stip the paint pretty well. The wood i was stripping wasn't the best to begin with, so im not sure how good it will be for what you need.

I guess testing on small section first and use gloves and glasses would be sensible advice too.

best of luck

[BrianT]

Yep Troy, have watched an antique dealer use caustic soda mixed with boiling water but ONLY to scrub down some painted concrete steps -worked a treat - not sure if it was the caustic or the fumes that were the most effective.

Other than that, see above re caustic and timber.

Brian @ Burra

[Grue]

If you use the caustic, don't leave it on for too long. As another member cautioned, it tends to get into the joints and ruin the glue.
Neutralise the caustic with an acid. Vinegar works. This MUST be done.

Grue

[TroyfromPerth]

yep - makes sense about neutralising with vinegar. I hadnt thought about it eating into glued joints either. Thanks for the info!

best regards
Troy

[con]

Greetings Petenchez,

I have another solution, it's brutal, but I have the reults to show for it.

I start by using a planer, yes, that is correct. I get what I can off with the planer. Flat surfaces on a door take about 10 minutes. Don't worry about planer marks if you get any at this stage

Then I use my trusty 4 inch belt sander, and no clog belts. Careful about going across the grain where style meets rail. If you do, don't worry, you can hand sand them out.

Inlaid moulding I carefully remove usiing a chisel I have for this job only. I either use new mouldings, which I stain up to match the old timber, or, I use snad paper wrapped around a piece of dowel to remove paint in concaves. For convex I fold sand paper over in figers and sand away.

For areas around glass etc, I remove glass. Dig putty out which my chisel. Another trick with old putty, is to heat it, and it crumles, making it easier to scrape away.

The most imprtant tool, it the Sandvik triangular scaper. This gets paint off on where machine cannot be used.

I also use a sgarp chisel for corners.

Little grooves etc, I use sanding belts cut into strips and fold them over so I can hang onto them. The backing is touch and stiffer than regular sand paper.

I gradually go up in the grades of sand paper over the whole door , or window.

I end up with fantastic results and do not buy expensive strippers.

You can email me at [email protected] if you need more assistance.

Regards,