just after some opinions please?
my 5(mk3) is due to have undersealing done on monday/tuesday this week, this i consider essential as most do.
i asked about getting cavity waxing done at the same time but was advised against it!! which surprised me somewhat.
has anyone else been given the same advice?
cheers
Interesting - did they give a reason Simon?
I would rate the cavity wax as more important than simple under-seal. And anti-stone-chip is something else again.
It takes longer to dry cavities than the outsides of the car.
Over the last fifty years all the cars we’ve owned which I injected Waxoyl into the cavities, subframes, and door pillars etc resisted the rust enough not to need any welding, they eventually only died because a crucial repair was uneconomic and I could by then afford a replacement. Those four cars (the last two I bought new) each lasted about twenty years.
The many second-hand cars we owned before I routinely applied Waxoyl all rusted and needed significant welding and none had been cavity injected although many had been under sealed. In most of these cases the rust came through from inside at about ten to twelve years old and the welding only lasted another couple of years before it rusted even worse than before.
Nowadays I prefer Dinitrol, but Waxoyl is still very effective.
To be honest if it has started rusting in the cavities then putting in cavity wax on top of rust is that going to fix anything?
Yes on a new car!!!
Getting into the back of the sill cavity on a Mk1 or Mk2 needs another hole drilled but that is not a show stopper.
Maybe the garage are trying to save you money, maybe the just do not want the hassle of you comming back with rusting in that area that the wax cannot stop if it is rusting already.
I’ve heard of cavity waxes blocking the drainage from the sills. This can result in water being trapped inside, which speeds the rusting process. If this happened, who would you blame? Probably the garage that sprayed the cavity waxes in for you. I’ve spoken to a few garages who won’t apply the stuff for this reason. But there are cavity waxes, and cavity waxes. They’re not all the same.
yeah, they say it can block the drains and cause condensation build up higher within the cavities, which in turn can cause rusting where it is more costly to repair.
i am stuck on this one.
on the other hand, my best mate has been in the body repair business all his working life practically (and he is older than me ) and he strongly recommends getting it done!
i have noticed no rust issues on my car and want to keep it that way for as long as possible.
Well if you want to do it, it is only say another £70 and you can make sure the drains at the jacking points are free so that problem is not an issue.
If you want to do it, just do it!
When I had my Mk3 waxoyled by MX5 City they injected it into all cavities. In particular they remove the black plastic strips covering the top of the cill in the doorway and inject the waxoyl. They then clear the cill drains. I then regularly insert a tie wrap into the cill drains to make sure that they remain clear.
All MX5s corrode in this area and as such MX5 City consider it is important that the inside of the cill is adequately protected. They also inject Waxoyl into all Mk1 and Mk2 cill repairs.
As long as you keep the drain holes clear I can see no valid reason for not injecting Waxoyl into the cavities.
i wish it was only £70 more.
i was intending to get it done professionally which equates to around £250
I have a two post lift and a compressor that can throw the stuff about.
The cost of blowing goo into the cavities is around £40 in matrials.
Removing plugs and putting a probe in the cavities is at most 30 minutes at say £50 and hour so £25.
Add vat say £75.
The cost of £250 to get the cavities done is not in my opinion a reasonable costs.
There are lots of other things to do like remove all the wheel arch liners and get goo in there then put them back, also cleaning the underside, touch up any paint loss and re underseal the underneath and possibly do the doors which in my opinion including the cavities will cost in the region of £400 including vat.
£250 just for cavities is just wrong!
As for blocking sill drains, just use common sense. Tubes of thin card pushed into each sill drain hole (slot) prior to injection, then remove a couple days after. Final check that they’re still clear couple of days later - job’s a goodun.
I guess the actual question is… if the inside of the cills have already started rusting by the time you get to them on a secondhand car (or even new one knowing Mazda) - is injecting cavity wax into them going to stop/reverse the rust?
As requested by PM, I have posted a link to drilling a hole into the rear sills for access.
Hi guys,
Having recently Waxoyled my recently-acquired NC, I strongly agree with the posters above who advocate getting it done, but it’s important to get the wax into the inside of the box sections notably the rear subframe.
It’s much easier if the wax is well warmed, so it flows easily and covers better, as recommended by waxoyl themselves. A drop of turps sub will also thin it down, but don’t overdo it to the point it actually runs off the surfaces. And yes - it will pong for a few days, and probably drip all over your garage floor.
Still a bloomin’ sight cheaper than £250 for a day’s work if you don’t mind getting dirty!
The underseal (Waxoyl’s own is good, and sticks well, unlike some ‘own-brand’ ones) is the easy bit, but be careful where you put it.
As regards the sill drains - be sure that you’re actually clearing the sill drains at the bottom of the seam weld - they are the little standouts ( 2 per side IIRC) which can and do get blocked by either road dirt or some grease monkey with an underseal spray like my mate’s was.
Easily cleared with the red tube from a can of WD40 or similar - they’re only little.
A hand-pump sprayer with a long thin tube and fine nozzle bent at the end to permit directing the spray works well if the wax is well warmed in my (limited) experience.
Just my thoughts…
Good Luck,
Aldi
Good DIY Mk3 underseal article.
http://www.mazdamenders.net/forum/viewtopic.php?f=42&t=2094&p=19650&hilit=mk3+underseal#p19650