Cavity waxing?

[slybunda]

Anyone do underbody waxing on their cars?

Iv got the waxoyl kit that has the 2.5l can and the pump thing that attaches to the top of it, it doesn't have a pipe that goes into cavities like sill or box sections so wondering what others use?

[Park Insurance Services]

I have been warned numerous times to avoid Waxoyl like the plague, Dynax S50 is what you really want. You can order a can with a tube nozzle that goes on the end of it - it is the best stuff you can get imo ~ Ben

[_Chris_]

I see 2 major issues with cavity wax.

 

From painful experience, if you do any welding on treated areas it works like candle wax and burns with great difficulty extinguishing. I nearly lost car and workshop. I ended up disconnecting the CO2 bottle from the welder, pulling open a rear trim and flooding the whole sill area with CO2 to put it out.

 

In my view, a thick layer of wax in the sills or other box areas will block any drain holes. Any area coated blind by shoving in a pipe and pumping is likely to create ridges which will trap water plus areas that have been missed altogether.

 

My preferred method currently is to use conformal coating as used in the electronics indistry to coat electronics for damp environments. It is moisture repellant and has fungicides etc. This just goes on like a laquer and can be sprayed inside sills with spray gun/ parafin gun and should only form a thin layer. It's available in rattle cans or liquid form.

 

[Infiniteblue]

Ive used all sorts of stuff, nothing sophisticated but seemed to have done the trick to good effect, but mainly on the regular periodic application of the prone areas if nothing else, know most of the drain hole application areas and yeah drain holes being able to drains likes been said is equally as important.

Now if youve got the waxoyl already u could always mix something to go with it too.

[Park Insurance Services]

21 hours ago, _Chris_ said:

I see 2 major issues with cavity wax.

 

From painful experience, if you do any welding on treated areas it works like candle wax and burns with great difficulty extinguishing. I nearly lost car and workshop. I ended up disconnecting the CO2 bottle from the welder, pulling open a rear trim and flooding the whole sill area with CO2 to put it out.

 

In my view, a thick layer of wax in the sills or other box areas will block any drain holes. Any area coated blind by shoving in a pipe and pumping is likely to create ridges which will trap water plus areas that have been missed altogether.

 

My preferred method currently is to use conformal coating as used in the electronics indistry to coat electronics for damp environments. It is moisture repellant and has fungicides etc. This just goes on like a laquer and can be sprayed inside sills with spray gun/ parafin gun and should only form a thin layer. It's available in rattle cans or liquid form.

 

 

This stuff is very interesting, I need something to reinforce the wheel arches on my fleet, a conformal coating sounds like just what I need. 

 

As for cavity wax, that is why I was recommended Dynax S50 instead of Waxoyl as the former is very viscous and can get into the gaps without blocking up holes. As for the latter, I have heard it described as liquid rust 

[Infiniteblue]

Yeah and surface preps supposed to be v important but obv thats easier said than done in many places, it doesnt 'seem' to have made any difference with mine but then again i cant see underneath or inside it

[_Chris_]

This is the section you need:

https://uk.rs-online.com/web/c/facilities-cleaning-maintenance/electronics-cleaners-protective-coatings/conformal-coatings/

This is what I usually use:

https://uk.rs-online.com/web/p/conformal-coatings/4090956

 

They seem to have changed brands since the last time I bought it in liquid form, I'll try and track it down.

 

What started me using conformal years ago I had a scrape on an old clio which leftt a big area showing bare metal. I sprayed some conformal over to stop it rusting before it went for repair. It was written off so I bought it back and drove it round in that state for years. No sign of rust.

 

For prep, it's best to get off as much rust as possible, obviously not possible inside cavities. I then usually use a converter such as kurust followed by red oxide primer then conformal coating. After that whatever coating / paint / underseal etc.

 

[slybunda]

What iv noticed with waxoyl people tend to confuse it with the underseal version of it Vs the thinner wax and oil substance from the same brand.

Either way I don't like putting it on bare metal and would prefer to primer first.

Attached document shows these other brands to be not as good as people claim.

Reading up on land rover forums people use the wax coatings for decades and have had good results.

 

That conformal coating seems hard like nail polish, won't it crack on a car with vibration etc and then let moisture in?

rusttest_noxudol_700_classic_monthly_uk.pdf

[_Chris_]

Looks an interesting article, I'll have a closer look at it later.

 

The conformal coating is designed for PCBs and there is some flex in those. All I can say is that it protected a rear wing panel on my clio for a decade, sprayed over bare metal and no other coatings.

The silicone based conformal tends to stay a bit tacky which is why I don't use it but it may be better as a final coating in non visible areas. I doubt you'd get anything to stick on top of it.

 

[slybunda]

Just wondering is a 24L air compressor with 9cfm rating any good for applying waxoyl type stuff or is it useless and only good for pumping up tyres?

[Infiniteblue]

Id have to double check but i think thats the same spec as mine which managed to spray oily stuff with the paraffin gun you can always thin (+ heat) it with something, thing is with the G7 its quite easy if u prise open the sill cover clips (or remove em) it increases drainage a lot and u can inject thro there, but tbh you really want to remove the sill covers anyway, its not worth doing a proper job without really cos thats where a lot of the corrosion/stuck on mud comes from, youll see if any areas need welding first and maybe where to conc on, and if so theres loads of access holes where you dont have to spray very far.

Tbh it mite be better in the spring but anyway i mainly used to squirt in thro the door sill covers then park on a slope so it runs to the ends 

[_Chris_]

From memory, the waxoyl presurises the can and pushes the wax out directly so works differently to a normal spray gun which uses a venturi to suck up the paint to mix with the airflow. I would imagine it will need to be thinned massively to work in this way, but then it would probably give a more manageable, thinner coat. I also remember heat being the prime thing that thinned the stuff.

 

[slybunda]

Hmm maybe get a hot air gun on the can or stick it on the camping stove?

[Xanadu]

Waxoyl - Dynax S50

[Old Red Celica]

Many years ago 1980 I started working in Wilco Motor Spares and we sold Waxoyl. Many people brought the kit back saying there was a nail stuck in the end of the pipe.

 

[bazz54]

The question for me is whether or not "conformal" coatings are intended for use on steels and I suspect the answer is no. The sort of corrosion you get on circuit boards is usually on tin, zinc and aluminium. Problems in electronics can be caused by corrosion which is truly microscopic ( the growth of whiskers which are much finer that a human hair). Conformal coatings are just thin coatings to minimise access of moisture on to electronic hardware where there probably is not going to be much moisture anyway, a bit like thin varnish.

 

I'm not a fan of what I call "gooey black stuff", typically, the tar-like stuff that's been flogged as "underseal" since the 1960's. I'm not a fan of Waxoyl. I prefer paints which include corrosion inhibitors in them; I'm thinking mainly of zinc phosphate, though there are others. It's the complicated electrochemical reactions of the inhibitors that do the business in helping prevent corrosion. Preventing corrosion is a huge multi-billion dollar business and there's some tremendous science that has gone in to it over the last 70-80 years.

[slybunda]

Can paints be sprayed into cavities like the sill? Paint such as zinc phosphate primer?

[_Chris_]

Paints can be sprayed into cavities, the biggest problem is access and how far a spray gun will spray. Access is down to design and is made much easier during or after rust repair when there ar big holes while repairing and the ability to leave a well places access hole plus a rubber bung. I normally use parafin guns which often come in the free tool kit with many cheap compressors - it may be possible to extend the nozzles further, I haven't looked as I haven't needed to yet.

 

 

Avoid going too hot with waxoil as there's a risk of explosion or fire. I think the instructions say to place in a bowl of hot water.

[slybunda]

On 07/12/2024 at 18:39, Xanadu said:

Waxoyl - Dynax S50

 

looking to go this route with the aerosol cans, cant be faffed with getting an air compressor and finding out its not good enough for the job.

realistically how many cans would one need for the gen7 cavities?

i see they do a 5L jug but then its not an aerosol so not sure how to go about spraying it

[slybunda]

So the noxudol cans have arrived, got 7 of them so hopefully that's enough.

Got a cavity wax gun on order and then it's just the air compressor left to get.

Need to research more on the compressor, may need to go the silent route since apparently they are very loud at 90 plus dB noise. Silent ones are around 80db