Removing shellac from a house

[jml170871]

If some one could please point me in a direction I'd be appreciative. I've been reading alot of the threads about removing shellac using metho & steel wool but my request is slightly different.

I've just bought a house that was owned by a (deceased) boat builder who shellac'd the entire extrior of the house.
The house is weather board (cyprus pine) buit in the 50's and according to neighbours the owner shellac'd the house about every five years and there was no rubbing back of the old stuff just paint the new stuff straight over the top.

Its been about 10 years now since the last coat was done and in some places its peeling and flaking off and looks awful.

My question is how is the best way to do a mass removal of shellac from the weather boards so that I can get them to a state where they can be painted with a conventional paint.

[astrid]

I would have thought that conventional shellac wouldnt stand the weather.
this is one for neil i think.
if it is shellac then normalt you could sand it back and paint over it but once again i dont knowif this works on the exterior.
test by soaking a small cloth with meths and sit it on one of the boards for about 10 min, if it softens then its probably a shellac base.
my worry would be the previous owners occupation if its a marine varnish it will be hard work i think

astrid

[scooter]

I reckon you will end up scraping off any loose stuff, & painting over the rest, same as repainting the house normally. Pretty much anything can go over the shellac, apparently, the only issue would be how well stuck to the weatherboards it is, hence removing any flaking/cracked stuff.

Scraper and/or wire brush maybe.


Cheers................Sean

[rsser]

Wouldn't be shellac. Some kind of varnish maybe.

[durwood]

I'm with Astrid on this one, seems highly unlikely its shellac.

It would only last a few months at best outside.

Varnish would be a more likely finish.

After you test with the metho try heat, if you have a heat gun and its varnish it should bubble up with the heat.

A small infra red bar heater would also blister the material, hold it close to the surface for a few seconds. If this is the case there are industrial heaters to do this properly.


It could be done with a torch which has a flame - LPG or a blow torch but this is not recommended unless you know what you are doing as it is easy to burn the house down.

Next way is a chemical paint stripper or other chemical method such as stripper pads ( stripper in a nappy form you place on the paint) these are not only messy but expensive especially if its the whole exterior of a house.

You could also sand it off but that too would be messy and expensive ( you would need a lot of abrasive paper) and the wood surface might suffer and need extra smoothing.

[Ashore]

Cladding Aluminium will last 40 years and you never paint again

[astrid]

I had to take 100 year of paint off the front of my place including calsomine
I bought a good heat gun with a temp control it took forever but this was because of the calso.
you should be able to set the temp fairly low for varnish.
as durwood says be extra careful arount the eaves or rotten timber as you could start a slow smoulder that you only notice too late and if a fire gets in under your roof

but this is avoidable if you use a sander under your eaves
beware a cheap gun, it wont last through the job.

astrid

[rsser]

I did two sides of a long tall Victorian weatherboard with a 7" disc sander and very coarse discs. It had been repainted over a poor surface so the bond wasn't tight. The trick was to come across sideways and the rim of the disc would virtually flick the old stuff off.

The downside as Durwood notes is the finish. With a light touch and then a quick wizz over with finer paper it came up pretty well. Certainly much quicker than using a heat gun or chemicals.

(The front however had two bay windows with all the mouldings; that took a heat gun and scraper and a week of hard graft. Never again.)

[MacS]

I would think twice, before using a heat gun or any other kind of flame on my house.

Have you given any thought to sandblasting off the coating, its a hellva lot safer, and it does a nice clean job.

[jml170871]

Thanks guys, you were right it was not shellac just large amount and numerous coats of lacquer.

Tried a couple of your suggestions and found a steady hand with a drill attached sanding disk seems to work nicely. I can see its going to be a time consuming and messy job.

Appreciate everyones input.