Underseal Professional Treatments?

[Michael Burridge]

My Z3 is a 2000 3.0 with 39000 miles - A great buy I think and I've really enjoyed it over the summer months. Now looking to get some work done underneath as I have a leaking steering rack - I've got all the parts for that but while under the car, I couldn't help noticing corrosion starting at the front of the inner sills and a little bit around the sub frames. All paintwork and panels are in great condition with no signs of rust but I'm wondering about the best way to treat the rust underneath and stop it from progressing.

My first thought was that I'd tackle it myself - take all trims off, sill covers etc and get sanding, rust treatment and wayoyl etc but I'm a bit stuck for somewhere to do it as the garage is too small and its peeing down outside!

So to get to the question, has anyone used a professional underseal service and is it worth considering? There is a local company which advertises Dinitrol treatment and their reviews are good. I have an appointment with them this Friday to do a thorough inspection and then recommend treatment. I'm pretty old school and would much rather do this myself but if they can do a good job for a reasonable price I'll be tempted.

Anyone have any experience / views on this please?

Thanks to those who have responded to my initial message - replies copied and pasted below. I've started as a thread in this forum as suggested....

From Ttony:

"Hi Michael, send GazHyde a PM and ask him to move this thread to the open forum in the Beauty Parlour section then you should get more replies.
Dinitrol has been around for many years now, it was being used at my local Ford dealership when I first got into the car trade back in the 70's.
Shame you don't have the space to do it for yourself as the satisfaction of doing it will be lost.

Tony."

My Reply:

"Thanks ttony - will do... Yes, I'd much rather do it myself and know that Its done right... Maybe I can find a way..."

From Colb:

"You will need somewhere dry to take the sills off and do any rectification work before treating with your chosen rust proofer. Threads on here with pictures showing how others have done this. I took my outer sill covers off and was lucky to find the inners rust free. Treated mine with clear Waxoyle and coated the inside of the outers with black Waxoyle before fitting them back on. I doubt that the Company you are looking at would remove the sills just inject the Dinitrol after drilling holes to access the cavities. I would take the sill covers off, trat any rust with rust convertor followed by red oxide paint followed by good thick coats of Waxoyle include the inside of the cover sills, put it all back together. If you want the whole car done by the Dinitrol company then it might be an option to remove the cover sills your self before taking it in, if thats possible I would also remove the wheel arch liners so they can get behind them as well."

My Reply:

"Thats great - thanks Colb. Yes - I've seen the work that others have done and posted here and its a really good source of reference. When I take the car in on Friday I'll ask if they'll take off the outer sills - they already state that they remove wheel arch liners etc so I'd imagine not a huge amount of work in addition to take the outer sills off too...

I would much rather do myself but lack of space is the issue - car is a nice tight fit in my garage, though I could do a side at a time which is an option. I guess my other concern is about having the whole underside coated - I know that main parts that don't require underseal will be masked off but things like brake pipes, cables etc which are fixed to the underside would undoubtedly be coated and I don't really know if that's a good or bad thing.

It might be that the cost is prohibitive anyway - I had one company quote £500 just from an e-mail enquiry and that was without inspecting the car (I'll steer clear of them). At least this company have a 30 min slot to do a proper inspections before quoting - their service includes a hot jetwash, steam clean, drying and then treating so sounds thorough and they provide photographic evidence of what they've done.

I'll report back after Friday - thanks again for responding."

 

[the Nefyn cat]

their service includes a hot jetwash, steam clean, drying and then treating so sounds thorough and they provide photographic evidence of what they've done.

If it doesn't include a fair bit of stripping and repairing it may not be worth it. As said above, there's several threads on here showing what people have done on their own cars, have a bit of a search and see what's involved. Some cars are a whole lot worse than others, and there's no way of telling till the sills are off.

 

[Althulas]

On any rusty areas I have used a angle grinder with wire brush attachments and taken back to metal. Then clean the metal with an acid etch the followed with another acid with a phosphorus component which leaves a protective Layer and buys some time upto three weeks to get some paint on. I have then sprayed over with a zinc undercoat paint followed by a two pack epoxy paint. After that I but atop coating of paint. If you search me you can see my slow progress thread. Time consuming but proper prep is the key. As for cavities there is a spray with a rust converter component.

 

[Faheem]

If I could afford it I would give my car to this place. After it's been restored the underbody on this car is like a piece of art. I think they said that the parts were north of £6k alone. So I reckon that with the labour something like this would easily cost £10-15k, maybe more.

Wouldn't want to drive it after though.

They take every component off, treat and remove any rust behind the existing underseal or on the chassis and then install new components or refurbish the old ones.

View: https://youtu.be/zfefuP9MKyw

 

[Michael Burridge]

Aaaah - thanks Faheem, that looks amazing... I wish I could take mine there too!

As I've been looking at this the steering rack has arrived. Looks OK (Not compared to your vid tho) and happily they have masked the plate underneath. This little lot needs to go on my car now - I just wish I had the space to at least do some of the work underneath while the old stuff is off but sadly not... Took a bit of inspiration from your pics for the parts - hopefully will make a bit of an improvement to the steering with this lot going on (Its not bad as is but be good to get all new parts to replace those that have been done as and when needed in the past).

Will report back after Friday on the underseal service I'll be visiting...

 

[Michael Burridge]

On any rusty areas I have used a angle grinder with wire brush attachments and taken back to metal. Then clean the metal with an acid etch the followed with another acid with a phosphorus component which leaves a protective Layer and buys some time upto three weeks to get some paint on. I have then sprayed over with a zinc undercoat paint followed by a two pack epoxy paint. After that I but atop coating of paint. If you search me you can see my slow progress thread. Time consuming but proper prep is the key. As for cavities there is a spray with a rust converter component.

Thanks Althulas - Great advice and I'll have a look at what you've done... May be a longer term project for me if I do it myself....

 

[Michael Burridge]

If it doesn't include a fair bit of stripping and repairing it may not be worth it. As said above, there's several threads on here showing what people have done on their own cars, have a bit of a search and see what's involved. Some cars are a whole lot worse than others, and there's no way of telling till the sills are off.

Agreed - Thanks. Will report back....

 

[Jonno Bee]

Hello Michael. I'm approaching the end of a restoration of the underside of my Zed. With the sills removed I found very little corrosion. I did replace one sill cover that had rotted through on it's trailing edge with no damage to the structure underneath.
The rear trailing arms, subframe and differential housing responded well to being cleaned up and repainted. With these components removed I was able to remove surface rust from the differential mounting bracket and repaint it.
I was very pleased at the lack of any serious corrosion on a twenty year old car and hopefully you will have the same experience.

Cheers,

Jonno

 

[Michael Burridge]

Hello Michael. I'm approaching the end of a restoration of the underside of my Zed. With the sills removed I found very little corrosion. I did replace one sill cover that had rotted through on it's trailing edge with no damage to the structure underneath.
The rear trailing arms, subframe and differential housing responded well to being cleaned up and repainted. With these components removed I was able to remove surface rust from the differential mounting bracket and repaint it.
I was very pleased at the lack of any serious corrosion on a twenty year old car and hopefully you will have the same experience.

Cheers,

Jonno

Hi Jonno - that’s really good to hear... The more I read, the more im convinced it’s something I can do over time rather than having to rely on someone else to rush to get it done.

Food for thought - thank you.

 

[t-tony]

Although you said that your garage has limited width Michael, do you have another outdoor space where you could put the car on stands and work on it outside (obviously weather dependant). I know some members have had to resort to this tactic.

Tony.

 

[Jonno Bee]

Hi Jonno - that’s really good to hear... The more I read, the more im convinced it’s something I can do over time rather than having to rely on someone else to rush to get it done.

Food for thought - thank you.

The key question Michael, is do you have the time, skills,tools, patience and inclination. I'm enjoying doing the work myself in a fairly confined 1930s era single garage. That said a good friend of mine with a Zed of similar age and condition had all the work done I did at his local garage in a fraction of the time I'm taking. He took all the suspension components for cleaning and repainting and presented them later for reassembly. The second question is how far do you want to go? Inspect your car honestly. Does it need a re-bush of suspension components, replacement brake pipes and hoses etc?. Having assessed what's required are you still up for the challenge? It is essential that you enjoy fixing cars in order to maintain the enthusiasm levels to complete the project.
Either way sorting the underside of your Zed should provide you with years of driving pleasure.

Cheers,

Jonno

 

[GZed]

You can get portable scissor lifts that let you lift the entire car about 4ft off the ground. @gookah has a great one that lets you tilt the front or the back right up in the air, so you can sit on a chair and work on the underneath in comfort. Solves the narrow garage problem

 

[Michael Burridge]

The key question Michael, is do you have the time, skills,tools, patience and inclination. I'm enjoying doing the work myself in a fairly confined 1930s era single garage. That said a good friend of mine with a Zed of similar age and condition had all the work done I did at his local garage in a fraction of the time I'm taking. He took all the suspension components for cleaning and repainting and presented them later for reassembly. The second question is how far do you want to go? Inspect your car honestly. Does it need a re-bush of suspension components, replacement brake pipes and hoses etc?. Having assessed what's required are you still up for the challenge? It is essential that you enjoy fixing cars in order to maintain the enthusiasm levels to complete the project.
Either way sorting the underside of your Zed should provide you with years of driving pleasure.

Cheers,

Jonno

Its a yes to all of those - the driver for wanting to get done quickly is that there's a recon steering rack, front wishbones, bushes, etc ready to be fitted and in my mind it would be good to get all done in one so to speak...

In the main, the underside isn't bad but it will certainly benefit from a bit of TLC...

Will keep you posted...

 

[Michael Burridge]

OK - so just been to https://pro-tectservices.co.uk/ and have had a good look at the whole underside of the Z3... Phew, it actually is really good with no problematic corrosion. Had a look at the work they do as well - its a good job which takes them three days, starting with thorough jetwash and steam clean underneath, Overnight in a drying booth, followed by treatment of any rust etc and then a full coat of dinitrol and injection of Cavity wax etc. They will remove all trim and sill covers too so that's re-assuring and they take full photographic records of all that has been done...

Will wait for the quote to come through but I'm expecting it to be around £700.00.... There's no doubt I could do it for less but I am tempted just for the peace of mind that its treated now and will continue to be good for years to come...

Thanks all for your thoughts so far on this thread..

 

[Althulas]

Might be of interest this process but I would use other products than used on here but shows you how water can get under some of the existing under sealant

View: https://youtu.be/YLAPGqakYXw

 

[Setch]

Have used Waxoyle, Dinitor and Bilt Hamber on my cars in the past. Wouldn't use Waxoyle, I found it goes hard and starts to lift and could allow water to prenetrate behind. Dinitrol is OK but doesn't appear to have the longivity of Bilt Hamber.

 

[ktnez99]

If I could afford it I would give my car to this place. After it's been restored the underbody on this car is like a piece of art. I think they said that the parts were north of £6k alone. So I reckon that with the labour something like this would easily cost £10-15k, maybe more.

Wouldn't want to drive it after though.

They take every component off, treat and remove any rust behind the existing underseal or on the chassis and then install new components or refurbish the old ones.

View: https://youtu.be/zfefuP9MKyw

What a very interesting video this is. Worth watching as full of tips and advice.

 

[ktnez99]

@dt7734 FYI

 

[Michael Burridge]

Have used Waxoyle, Dinitor and Bilt Hamber on my cars in the past. Wouldn't use Waxoyle, I found it goes hard and starts to lift and could allow water to prenetrate behind. Dinitrol is OK but doesn't appear to have the longivity of Bilt Hamber.

Thanks Setch - certainly worth considering.

The things that were really selling the idea of having this done professionally to me were the timeframe and the my lack of space to be able to do this in one go.. I've now received the quote that was promised and they are fully booked up till 19th November. They do a good job from what I've seen but this really pushes me back towards doing this myself.

Will have a good look at the options available - Waxoyl, Dinitrol and Bilt Hamber... Theres a number of products from Bilt Hamber as you'll know - my uninformed view is that I should be looking to use the following (Of course after removing trims and sill covers, thoroughly cleaning, drying and removing as much surface rust as possible):

1. Hydrate 80 Rust Killer for treatment of any surface rust (or should I be using Deox Gel?)
2. Dynax UB Anti Corrosion Under Body Wax Protection Prevent Rust for coverage of the underside of the car (masking bits I don't want to cover).
3. Dynax S-50 Extreme Anti-Corrosion Wax for cavities.

Opinions welcome and one question please... I've also seen Electrox Zinc Rich Corrosion Protection by Bilt Hamber - should I be using this for example under the sills after step 1 above? and if so, presumeably I then continue to step 2 and cover everything that I've already done with the Electrox?

Thanks

Michael

 

[Mnbrennan]

Have a look at my thread, I did a full underside protection

https://zroadster.org/threads/introducing-rhubarb.13136/page-9#post-414439