# WD-40 effects on gelcoat & fiberglass?



## night0wl

Hi all,

Recently, accidentally discovered something. While lubricating something or other on my Beneteau 343, I sprayed some WD-40 (wasn't using it for lubrication, just squeezed the trigger in my tool bin) on my gelcoat.

This area of gelcoat had some nasty wax buildup that had discolored badly. In my part of Fort Lauderdale, we get a LOT of airplane, highway, and general soot pollution due to a powerplant incinerator nearby. I tend to follow MaineSails excellent guide on boat maintenance, but Collinite has a nasty habit of discoloring after 2-3 months. Strangely enough, the WD-40 accidental spray shot took the nasty wax and dirt right off!!!


Previously, when its time to strip the wax down, I rely on successive washes of Dawn soap, and even then, ultimately have to rely on some heavy solvents like Acetone, MEK, or Interlux 202 to get it to bare glass. I *HATE* those solvents as I know they are bad long term for the gelcoat. But, so far as I can tell, WD-40 is a lubricant more than a solvent. 

Whats to prevent me from using this stuff to strip/clean the boat? Much cheaper than dedicated boat wax removers (such as 3M's aerosol). 

Any issues with staining? Thoughts?


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## mitiempo

WD40 is more than 50% solvent with a light mineral oil as one ingredient - about 25%.

It shouldn't do any damage. Acetone will not do any damage either as it flashes off pretty quickly.


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## night0wl

So, as a solvent, it will eventually harm the gelcoat just like the Interlux 202. Solvents strip the gelcoat of lubricants/waxes and cause it to get porous...eventually causing even more dulling.

But, i just cant get these stains without solvent or some kind of abrasive (aquabuff 2000 worked, so did meguires flagship which has silica in it).

So please rate the following solvens in terms of least harsh to most harsh...I've included prices from home depot's site for a gallon:

WD-40 ($17)
Acetone ($17)
Paint Thinner ($11)
Mineral Spirits ($11 for eco, $14 for non-eco friendly)
Laquer Thinner ($18)
Turpentine ($16)


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## mitiempo

Gelcoat is porous. The wax and dirt will be removed by any good strong solvent product. Gelcoat itself, really fiberglass resin and pigments, is pretty indestructible. I have never seen an example of gelcoat damage from solvents in over 40 years of fiberglass boat ownership.

I would use acetone because it is strong enough to remove any dirt etc and it does not leave any residue like wd40 and some other solvents. A good fiberglass cleaner should remove any other stains. Failing that wet and dry sandpaper used wet starting with 400 or 600 grit and working to finer grits should remove any surface staining left. Then wax to protect.


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## DearPrudence

I don't mean to hijack, however this is related in that in involves an aerosol on gel-coat.  In the spring of the year Mayfly's are incredibly thick here on Lake Erie. Bird droppings and spiders are also a constant. I was wondering if using a cooking spray such as "Pam" on the deck would be helpful as far as clean up is concerned. Please don't laugh...I haven't tried it, yet. But it is frustrating when you spend all day swabbing the decks only to have it consumed by Mayfly carcasses the next day.


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## night0wl

mitiempo said:


> Gelcoat is porous. The wax and dirt will be removed by any good strong solvent product. Gelcoat itself, really fiberglass resin and pigments, is pretty indestructible. I have never seen an example of gelcoat damage from solvents in over 40 years of fiberglass boat ownership.
> 
> I would use acetone because it is strong enough to remove any dirt etc and it does not leave any residue like wd40 and some other solvents. A good fiberglass cleaner should remove any other stains. Failing that wet and dry sandpaper used wet starting with 400 or 600 grit and working to finer grits should remove any surface staining left. Then wax to protect.


Here is why I want to avoid strong solvents: Be careful with acetone and gelcoat. - Moderated Discussion Areas

Now, the guy left an acetone soaked rag on his gelcoat for days on end, but still, I'd imagine that there is a lesser effect each time you use solvent on gelcoat.

That being said, the effect is still likely very minor....but nevertheless, I'd like to use the least aggressive solvent that still gets the job done. Hence the need to rank those solvents mentioned above!


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## mitiempo

The only 2 solvents you listed that do not leave a residue behind are lacquer thinner and acetone. The others will leave oil or something else behind. I prefer a solvent that leaves nothing behind that will then require cleaning.

For an acetone soaked rag to do damage it would have to have acetone in it for a while. Acetone flashes off so fast that the rag should be dry in a short period of time.


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## mitiempo

DearPrudence said:


> I don't mean to hijack, however this is related in that in involves an aerosol on gel-coat.  In the spring of the year Mayfly's are incredibly thick here on Lake Erie. Bird droppings and spiders are also a constant. I was wondering if using a cooking spray such as "Pam" on the deck would be helpful as far as clean up is concerned. Please don't laugh...I haven't tried it, yet. But it is frustrating when you spend all day swabbing the decks only to have it consumed by Mayfly carcasses the next day.


Clean and wax the fiberglass. What sticks to fiberglass will not stick to a well waxed surface. Pam will probably attract bugs.


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## mitiempo

night0wl said:


> Here is why I want to avoid strong solvents: Be careful with acetone and gelcoat. - Moderated Discussion Areas
> 
> Now, the guy left an acetone soaked rag on his gelcoat for days on end, but still, I'd imagine that there is a lesser effect each time you use solvent on gelcoat.


Wipe with acetone on a rag and dry. Don't leave the soaked rag on the fiberglass afterwards. If the solvent is not stronger than the stain it will not be removed. Using multiple solvents is probably worse for the gelcoat than cleaning it properly with acetone to start with.


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## paul323

Remember that when using powerful solvents, let rags totally dry out or dispose of carefully. If you bundle up old rags, or put them in a confined space, there is a risk of combustion/fire (I was always told spontaneous combustion, but am not sure if that is an urban myth). Just saying - using solvent, putting a load of used rags in a bucket which is in the engine compartment - not a good idea.

Acetone is probably the best degreaser you can use. I don't think an acetone wash will damage the gelcoat, but I know it will damage you; so if you are cleaning large surfaces please use a correct respirator (one with carbon filters, not a dust mask as I once saw) and correct gloves/protective clothing.


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## jfdubu

First, WD-40 is a great cleaner/degreaser/lubricant and I always have 2-3 cans of it around. As a cleaner vs Acetone you have much more "working time" to use it against aggressive stains. you can always use acetone to wipe the WD-40 residue off very quickly if it's not wanted.

Second, spontaneous combustion is NOT a myth. We had a painter dispose of a handful of lacquer thinner soaked rags in a dumpster, they ignited and almost burned the building down. He disposed of them right before going home and the fire started about two hours later. Be very careful how you store/dispose of any rags and such soaked with anything combustible. It's true that you need three things for a fire, fuel, air and ignition. Fuel and air are easy to see in rags and if any the vapors elevation in temperature to the flash point,, ignition, spontaneous combustion. it happens all the time.

John


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