Paint stripping cast cement

[TexasRed]

We've started work prepping the house for painting and made an interesting discovery.

Some of the detail moulding I previously posted about is not wood or plaster, but cast stone Huh?! This was a real surprise. Interestingly, The egg & dart seems to match the cast stone detailing on the first bank building in town - the original owner/builder of our house was the president of that bank.

After a closer look, the E&D trim is applied in sections approx. 16" long.

Egg & Dart

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Egg & Dart stone revealed

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These wreaths surely have more crisp detail than currently revealed. Far too many layers of paint.

Hops Wreath

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The carbide scrapers are not useful or practical on this - the substrate easily chipped (plus, they are just too intricate and numerous). Next tried a bit of chemical stripper I had on hand - it kind of worked, but not well.

Wreath after stripper

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? Anyone have experience with cast stone moulding like this? It is out of my realm of knowledge as to what type of masonry we are dealing with. Here is a close up of the material. Pic taken through a loupe for magnification.

Magnified view of cast stone

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At a glance it looks much like cement. I have verified all of this moulding and the wreaths were original to the house in 1905, definitely not modern material.

? We want to clean these up before re-painting. Would a stripper formulated for masonry be a good next step? Any preferred brands come to mind?

? Lastly... Speculation on how these elements may have been attached? The egg & dart would be much easier to work on if it was flat on a workbench instead of overhead, under the eave. Am I just asking for trouble trying to remove these?

Thanks for any advice or suggestions

[Olson185]

By definition, it's either 'cast concrete' or 'carved stone' (incl. limestone, imo); while others may use made-up terms (some of which are quite common/popular), they're wrong in using them (but, then, I would never call any sort of engineered flooring "hardwood"; nor are all floors "hardwood" just because they're tongue-n'-groove).

Just to be sure, note that concrete can take many forms (of appearance) due to the size and blend (content) of its aggregates, as well as, the nature of whatever it is holding the aggregates together (esp. pre-Portland cement).

I've worked on sites dealing with cast concrete features but my involvement was primarily limited to hoisting them down once removed from a facade and then painting them after being restored and re-installed. I do know, they were encapsulated with some sort of sealer after restoring and prior to being repainted.

Oh, and all of them had metal posts (ie. unthreaded bolts) sticking out of the back of them. These posts held them in place, as well as, a "skim coat" of mortar (underneath). For something like you pic'd, I wouldn't be surprised if there are wire hangars/hooks of some sort.

[Willa]

Look up "Peel Away" by Dumond Chemical. There are different formulations for different surfaces. It is a caustic paste that is applied, then wrapped in a special paper to keep it moist. It can get through more than 20 layers of old paint, while leaving the original surface untouched.

This is probably the best product for this application given the complex shapes, undercuts, etc. I don't think you will get very far using a scraper designed for flat surfaces ?

The product is somewhat pricy as I recall, but works very well.

[phil]

instead of trying to scrape , if your stripper will dissolve the paint you could try a plastic scrub brush. toothbrushes will dissolve but you might find a nylon scrub brush that's suitable and wont' dissolve in the stripper. of course wear a face guard if you are doing this as you dont' want it in your face never mind your eyes. if stripper will work Lacquer thinners may work as well, you might try a natural bristle paintbrush.

[TexasRed]

Thanks for the feedback.

Went to the hardware store to buy the Peel Away (thanks Willa). Saddly, they no longer carry it. I looked at the other 8 paint removers they stock, but decided not to buy yet another can of "something".

Phil - I like your suggestion of trying a stiff brush. The paint is sooo thick - your idea might work great if I can get a product that will dissolve the paint.

The salesperson suggested using a heat gun. (Duh, why hadn't I thought of that?!?) It worked very well to soften up the heavy layers of paint. The issue of trying to not damage the substrate while scraping the paint away is still a problem.

The wreaths do appear to be cast concrete but easily chipped. I think I could clean these up - wish there wasn't 36 of them!

Partial Wreath - after heat gun

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The egg & dart moulding is made of a different product altogether...maybe plaster after all?!?

Egg & Dart - after heat gun

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This stuff seemed really soft after removing the paint and retained the heat from the heat gun for a long time. It was a challenge to not gouge the moulding in the process. Tomorrow I will see if I can remove a complete section so I can work on it at a workbench. ((sigh)) We are undecided if this trim is worth the many hours of work that would be involved to strip or if we should just replace it - provided I could find replacement in the same size/scale.

To be continued.....

[phil]

they are beautiful details and worthy of saving. It definitely requires some labor of love and lots of time but I sure wouldn't want to loose those features if they were part of my house. It looks like they must be repainted so you probably dont' need to remove every thread of color.

[Willa]

Contact Dumond directly to see who is your closest Peel Away distributor. It won't damage cement or plaster and is probably your best bet for this application:

https://www.dumondchemicals.com/pro-peel-away-1.html

[TexasRed]

Thank for the suggestion Willa. I did just that and we drove the 40 miles yesterday to pick some up. We have several test areas going as I speak. Tomorrow morning will be the tell all.

We were able to remove 1 section of the egg & dart moulding (pics tomorrow). It is a huge beast of cast stone (concrete) weighing about 15 lbs. for an 18" section. I'm excited to see if it will be easier to strip with the Peel Away. Forward progress is being made!

[heartwood]

I've used dumond chemical products with decent results...typically, it is a two coats system...apply, remove as much paint as possible then apply again...
I have used peel away 6 and 7 and smart strip...when I asked the chemist at dumond about the differences between the products, he chose not to elaborate by said the products contained alcohol...rather than purchase the expensive paper, use saran wrap to cover and keep moist...once it dries out it stops working...

peel away one requires neutralization with vinegar...6,7 and smart strip are ph balanced...

good luck! those details deserve to come alive once again...
...jade

[TexasRed]

I've used dumond chemical products with decent results...typically, it is a two coats system...apply, remove as much paint as possible then apply again...
I have used peel away 6 and 7 and smart strip...when I asked the chemist at dumond about the differences between the products, he chose not to elaborate by said the products contained alcohol...rather than purchase the expensive paper, use saran wrap to cover and keep moist...once it dries out it stops working...

peel away one requires neutralization with vinegar...6,7 and smart strip are ph balanced...

good luck! those details deserve to come alive once again...
...jade

Thanks Jade! Knowing those extra bits of info are really helpful.

The trial of Peel Away 1 was semi-successful. It only loosened up the top 2 paint layers on the egg & dart trim. I don't think we gave it enough time. We will be doing another test run tomorrow morning. We are leaving it on one of the wreaths for another 12 hours. Hoping for better results. I am determined to revive these unusual trim details.

As always, greatly appreciate your valuable input!