WD40 on concrete? Heat resistance? And for how long is it flammable?

[Krome10]

Hi all

I am having a wood stove fitted soon and it will be sat on a concrete hearth. I want to enhance the colour of the concrete, and have read about people using WD40 to enhance the colour of various stones , slate, etc.

Do you think it would be ok to use WD40 in this way?

What kind of heat resistance does it have?

And, if sprayed on concrete, would it remain flammable or would it lose its flammability (and if so after how long)?

Many thanks

 

[Dee J]

Doubt it would be a problem after the propellant has evaporated / dispersed. So probably minutes only. Don't know if it would be my first choice of product thought. Lots of much nicer stains, oils, waxes, paints, sealants etc available

 

[heronviewer]

Why not build your hearth using coloured paving slabs ? WD40 doesn't sound a good idea to me.

 

[Noel]

Hi all

I am having a wood stove fitted soon and it will be sat on a concrete hearth. I want to enhance the colour of the concrete, and have read about people using WD40 to enhance the colour of various stones , slate, etc.

Do you think it would be ok to use WD40 in this way?

What kind of heat resistance does it have?

And, if sprayed on concrete, would it remain flammable or would it lose its flammability (and if so after how long)?

Many thanks

There's virtually no heat coming out from the underside of a stove so nothing to worry about in that regard. Obviously the area below and in front of the door if there's anything falls out is important but as said, whatever you put on the concrete will be dried/cured.
I'd look for some slate perhaps, if budget permits.

 

[MARK.B.]

You could just add a colour pigment to the concrete no help if the hearth is already in place though

 

[Trainee neophyte]

If it were me, I would make up a small bit of concrete and test it first, and then throw some ash on top and see what that does. I would be more worried about whether it stays put long term, and how it cleans up after spillage.

 

[Robbo3]

My wood burner stands on a screeded floor finished with floor paint. No problems even with red hot embers.

 

[Krome10]

Many thanks for the replies

Why not build your hearth using coloured paving slabs ?

We don't want to / can't raise the height of the hearth, so adding anything in that sense isn't an option...

There's virtually no heat coming out from the underside of a stove so nothing to worry about in that regard.

Interesting you should say that, as some stoves only need a 12mm hearth (usually stoves on legs of ??mm height) whilst others need a full monty constructional hearth. I think the threshold is 100C. Mine needs the full on, so will be 100C+.

no help if the hearth is already in place though

It is indeed already in place


I gave the hearth a little soak this evening, and I like the look of the concrete when simply wet with water, so anything that would darken and enhance the colour the same way water does would be perfect. I'll take a look at stone sealers but if anyone knows of specific products that would be most helpful.

I really don't need much either.... We're talking the surface area of a sheet or two of newspaper at most!

Thanks again to all repliers

 

[Noel]

Many thanks for the replies



We don't want to / can't raise the height of the hearth, so adding anything in that sense isn't an option...


Interesting you should say that, as some stoves only need a 12mm hearth (usually stoves on legs of ??mm height) whilst others need a full monty constructional hearth. I think the threshold is 100C. Mine needs the full on, so will be 100C+.



It is indeed already in place


I gave the hearth a little soak this evening, and I like the look of the concrete when simply wet with water, so anything that would darken and enhance the colour the same way water does would be perfect. I'll take a look at stone sealers but if anyone knows of specific products that would be most helpful.

I really don't need much either.... We're talking the surface area of a sheet or two of newspaper at most!

Thanks again to all repliers

I was assuming you had an ash box on your burner and burning wood.

 

[Robbo60]

Hi all

I am having a wood stove fitted soon and it will be sat on a concrete hearth. I want to enhance the colour of the concrete, and have read about people using WD40 to enhance the colour of various stones , slate, etc.

Do you think it would be ok to use WD40 in this way?

What kind of heat resistance does it have?

And, if sprayed on concrete, would it remain flammable or would it lose its flammability (and if so after how long)?

Many thanks

My wife cleans our slate hearth with WD40 and it works well. I would imagine concrete will be hard to clean?

 

[Richard_C]

How about dilute pva glue as a seal? If you use the waterproof dries clear kind it could be wiped clean. As suggested above, a few test pieces of concrete and try things out.

 

[Krome10]

I was assuming you had an ash box on your burner and burning wood.

You're right, there is an ash box, and so the main firebox won't be in direct contact with the hearth. But I still presume it must get to over 100C as to meet the 12mm thick hearth requirement you have to add 100mm legs to the stove (even the 50mm legs AND ash box isn't enough to meet the requirement).

My wife cleans our slate hearth with WD40 and it works well. I would imagine concrete will be hard to clean?

It does seem to be with slate that I'm mostly hearing it is used with. Why slate more than other material I don't know;; although it could be as simple as how popular slate is for hearths.

Cleaning? What's that? Tbh, an occasional vacuum is probably all it will see. Maybe a scrubbing bruh once every few years. Our house is quite "agricultural"!

How about dilute pva glue as a seal? If you use the waterproof dries clear kind it could be wiped clean. As suggested above, a few test pieces of concrete and try things out.

The use of PVA has come up a few times in the last couple of weeks, for this and other things too. I've never used before (well, maybe I did at primary school), so might have to get a bottle as it would seem it's quite a multi tasker!

Big thanks for all the replies. Keep warm out there!

 

[Phil Pascoe]

If you must use WD40

https://www.tesco.com/groceries/en-GB/products/294834669

 

[Krome10]

If you must use WD40

https://www.tesco.com/groceries/en-GB/products/294834669

Corrr, that's a good price, thanks for the heads up. However, I have a new-ish trade size can which I guess will last me at least a decade. That was part (a small part) of the reason to consider it... I was being "thrifty"

 

[Noel]

You're right, there is an ash box, and so the main firebox won't be in direct contact with the hearth. But I still presume it must get to over 100C as to meet the 12mm thick hearth requirement you have to add 100mm legs to the stove (even the 50mm legs AND ash box isn't enough to meet the requirement).



It does seem to be with slate that I'm mostly hearing it is used with. Why slate more than other material I don't know;; although it could be as simple as how popular slate is for hearths.

Cleaning? What's that? Tbh, an occasional vacuum is probably all it will see. Maybe a scrubbing bruh once every few years. Our house is quite "agricultural"!



The use of PVA has come up a few times in the last couple of weeks, for this and other things too. I've never used before (well, maybe I did at primary school), so might have to get a bottle as it would seem it's quite a multi tasker!

Big thanks for all the replies. Keep warm out there!

No, not on our burner anyway. Barely 15/16c as I can put my hand right under it to the back. Assume the 12mm requirement is really just common sense. A wood burner can get up to 350c odd on a good day. They can crack, fall over spill etc.

 

[Krome10]

The hearth requirements come from building regs. I'm quoting from memory - which is never a wise thing - but OI think it's along the lines of... If the stove is tested as being under 100C on the underside, then a 12mm hearth is sufficient. If not, a full constructional hearth (125mm thick, and a few other stipulations) must be used.

An interesting aside... One of the stoves we had shortlisted but later ruled out was this:

https://www.woodwarmstoves.co.uk/stove-range/wildwood/
Like the one in the promotional photo there at the top of the page. Contrary to what the photo might have you believe, there is a warning in the user guide that you must not store logs beneath it whilst the stove is in use... Which makes for a pretty useless log store!!! But the reasoning is that it gets too hot on the underside and it would be a fire risk.

Anyhow, back to topic. I have a small bottle of LTP colour enhancer so might give then a go to get the colour up.

Many thanks for the reply

 

[MARK.B.]

My daughters dog when visiting us will often sleep quite happily under the wood burner with no ill effects

 

[Krome10]

My daughters dog when visiting us will often sleep quite happily under the wood burner with no ill effects

Wow - your wood burner must have tall legs! What type do you have?

Ours doesn't have any legs, so I think an ant wold have a hard time sleeping under it; let alone a dog!

 

[MARK.B.]

No idea of the make, it was bought from Ebay many years ago and still going strong, the legs are 7" and her dog is a small highland terrier so has no problem fitting underneath.