Advice on rust protection/undercoat/paint/underseal

[Márquez6]

I have cleaned,wiring brushed,degreased and applied bilt hamper hydrate 80 were needed ,what do I need now for the next step on the areas below..? Do I need to coat the fuel tank with anything? Any advice would be appreciated , i don't have a compressor and all the work in done on axle stands

 

[JamesBryan]

Fuel tank is plastic, so that won't rust 😉

 

[Márquez6]

*Hamber

 

[Márquez6]

Fuel tank is plastic, so that won't rust 😉

Renault seemed to have sprayed something on it..

 

[JamesBryan]

Renault seemed to have sprayed something on it..

I think it's just built up dirt.

 

[plenty]

Bilt-Hamber Dynax UB (dark coloured) or UC (clear) works well and comes in aerosols which are really easy to use. I've heard good things about Lanoguard but haven't tried it myself.

 

[dave120]

The car looks very solid mate.

 

[Márquez6]

Bilt-Hamber Dynax UB (dark coloured) or UC (clear) works well and comes in aerosols which are really easy to use. I've heard good things about Lanoguard but haven't tried it myself.

I have already bought that for the final coat, I was looking for something for the axle,chassis and underside before that.I was thinking a primer/paint for the rust/metal,epoxy for the axle and stone chip for the underside.

 

[Márquez6]

The car looks very solid mate.

I have spend days on my back cleaning 16 years of dirt and grime of it.it's a nightmare of a job.

 

[dave120]

Bilt Hamber Dynax UB as some have said previously or why not just use black hammerite then waxoyl.

 

[npt]

Something like dinitrol or schultz do various coatings, the bilt hamber stuff mentioned is good but not good enough for wheel arches or areas that are heavily impacted by in the wet, lucky if it holds up for a year from what I've seen

 

[Márquez6]

Something like dinitrol or schultz do various coatings, the bilt hamber stuff mentioned is good but not good enough for wheel arches or areas that are heavily impacted by in the wet, lucky if it holds up for a year from what I've seen

The arches have been ok with nothing on them,I was expecting to fine more rust underneath than I did..

 

[Jack1998]

@Márquez6
Have just done the same thing with my phase 1.
I would say if you can, drop the tank out, there are two sections of metal where the outer bolts of the fuel tank go. Can't be accessed without removing the tank but would imagine they would be rusty, mine were, they are basically just a little dirt shelf. Plus all the metal under the tank is completely unprotected.
I used dinitrol products, Dinitrol 3125 and Dinitrol 4941, they are grease based so will last ages, won't store moisture underneath leading to rust down the line, is self healing and sets to sort of a tacky hard coating so won't melt and drip in hot weather.
Just my two cents, hope it helps🤙

 

[Márquez6]

Bilt Hamber Dynax UB as some have said previously or why not just use black hammerite then waxoyl.

I sprayed behind the tanks with Bilt Hamber surfex HD and cleaned with a foot long angled brush/jet washed.
Before reading your message I was given advice by a rust specialist they said the same as you( Dinitrol 4941,Dinitrol 3125)i have ordered the Dinitrol 4941 but left the Dinitrol 3125, I think it's the same as the Bilt Hamber S-50 I already have but not used yet..thanks anyway for the advice.

 

[Jack1998]

I sprayed behind the tanks with Bilt Hamber surfex HD and cleaned with a foot long angled brush/jet washed.
Before reading your message I was given advice by a rust specialist they said the same as you( Dinitrol 4941,Dinitrol 3125)i have ordered the Dinitrol 4941 but left the Dinitrol 3125, I think it's the same as the Bilt Hamber S-50 I already have but not used yet..thanks anyway for the advice.

Just for reference I used 5 tins of Dinitrol 4941 and that covered the entire underside, plus some in the engine bay.
Just had a dig through my project thread pictures, the sheared bolt is the outer mounting bolt for the fuel tank and that's the bit of metal I was on about, essentially a dirt shelf. All that area was covered in surface rust on mine.

^also a quick picture of the underside without fuel tank in place before I treated anything, 0 under seal or protection under there from factory!
Again, hope this helps.

 

[Márquez6]

I don't want to take stuff off when I do things tend to break,I'm trying to do it all on axles stands,if I can see it I'll coat it and if I can't I'll use the long spray tube.

 

[Pegasaurus Rex]

It’s worth dropping the rear beam in my experience mate. It’s a hassle but the area is an absolute rust trap. In fact the backend of these cars is where the problems mainly lie. Fuel filler cap rear sills and the rear suspension, beam and crevices. It’s a shitty job but catching it now will give you years more driving. Many owners ignore this now will have either huge bills in the future or MoT failures for sure

 

[Jack1998]

100% agree @RustyMojo

That was the underneath my beam mount.

 

[Márquez6]

It’s worth dropping the rear beam in my experience mate. It’s a hassle but the area is an absolute rust trap. In fact the backend of these cars is where the problems mainly lie. Fuel filler cap rear sills and the rear suspension, beam and crevices. It’s a shitty job but catching it now will give you years more driving. Many owners ignore this now will have either huge bills in the future or MoT failures for sure

If the rear beam needs to come off to fit new bushes the garage can do that bit,while they're at it take the fuel tanks off.

 

[Pegasaurus Rex]

If the rear beam needs to come off to fit new bushes the garage can do that bit,while they're at it take the fuel tanks off.

It doesn’t no, they can drop the tank slightly to get the beam out without removing the brackets. However if you are doing the job properly I would suggest dropping the beam at least and repairing/protecting under the brackets.

I will be attacking mine at some point having already done the work on my old car. It’s the only way it will be sorted properly. Not looking forward to dropping the tank as it’s currently half full. So may wait until it’s nearly empty first! Which will be an age considering how little it gets driven.

Also while your around there I urge you to check behind the petrol filler cap! Suspect many people are going to need new inner wings if they don’t address it soon. Even if the rust can’t be seen from the fuel filler i can guarantee it will be right in the top recess of the inner wing. Mine was just surface rust. But another year or so and it would’ve been holes and dust

 

[frayz]

Well worth getting in and treating the areas behind the filler. Dirt and moisture sits there and has nowhere to go but rot the metalwork.
mine was very light surface rust because it was caught early. It’s now epoxy inside and out.

 

[Márquez6]

It doesn’t no, they can drop the tank slightly to get the beam out without removing the brackets. However if you are doing the job properly I would suggest dropping the beam at least and repairing/protecting under the brackets.

I will be attacking mine at some point having already done the work on my old car. It’s the only way it will be sorted properly. Not looking forward to dropping the tank as it’s currently half full. So may wait until it’s nearly empty first! Which will be an age considering how little it gets driven.

Also while your around there I urge you to check behind the petrol filler cap! Suspect many people are going to need new inner wings if they don’t address it soon. Even if the rust can’t be seen from the fuel filler i can guarantee it will be right in the top recess of the inner wing. Mine was just surface rust. But another year or so and it would’ve been holes and dust

I have cleaned /sanded behind the filler cap,it wasn't to bad just needs painting now.I didn't take the front off because there's funny shaped screws.I did take the rear arch liner off and found a farmers field behind it.,I also found rust starting under the back bumper,the seam sealent had water trapped underneath it.

 

[Márquez6]

Well worth getting in and treating the areas behind the filler. Dirt and moisture sits there and has nowhere to go but rot the metalwork.
mine was very light surface rust because it was caught early. It’s now epoxy inside and out. View attachment 1523362

That's a very good job.

 

[Jack1998]

I have cleaned /sanded behind the filler cap,it wasn't to bad just needs painting now.I didn't take the front off because there's funny shaped screws.I did take the rear arch liner off and found a farmers field behind it.,I also found rust starting under the back bumper,the seam sealent had water trapped underneath it.

Just drill them out, I replaced mine with normal bolts after.
Once you've drilled them out it's only one jubilee clip and a 13mm nut and the whole filler neck will come off the tank and out the way.
Then it's only 4 nuts, 3 fuel hoses and an electrical connector and the tanks out 🤭

 

[Pegasaurus Rex]

I have cleaned /sanded behind the filler cap,it wasn't to bad just needs painting now.I didn't take the front off because there's funny shaped screws.I did take the rear arch liner off and found a farmers field behind it.,I also found rust starting under the back bumper,the seam sealent had water trapped underneath it.

Mine looked like there was little there

Then I rubbed it all back

outside looked just like light bubbling

until you remove the flap and filler

All treated and repaired.

 

[Márquez6]

Mine looked like there was little there
View attachment 1523393Then I rubbed it all back
View attachment 1523392
outside looked just like light bubbling
View attachment 1523394
until you remove the flap and filler
View attachment 1523395
All treated and repaired.
View attachment 1523396View attachment 1523397View attachment 1523398View attachment 1523399

Another good job,you two should start up a business refurbishing petrol caps,there must be 1000s want doing.

 

[riber3]

Great Job have you tried using phosphoric acid on some of your metal parts as this helps convert rust back to iron as well as give protection

 

[Greeny.]

@RustyMojo Yours is fairly bad there, good job catching it before it got any worse! I just finished mine this evening, surprising how much is hiding behind the flap tbh, mine looked fine other than the bolts being rusty but when everything was removed had a fair bit of service rust to sort, I was semi suprised as the car just sits in the garage these days, but perhaps the damage was done earlier in its life.

 

[Pegasaurus Rex]

@RustyMojo Yours is fairly bad there, good job catching it before it got any worse! I just finished mine this evening, surprising how much is hiding behind the flap tbh, mine looked fine other than the bolts being rusty but when everything was removed had a fair bit of service rust to sort, I was semi suprised as the car just sits in the garage these days, but perhaps the damage was done earlier in its life.

It’s actually wasn’t that bad to be fair, I have done a couple of these now. Was very solid behind. Big problem is the little strip beween the opening and hinge. Luckily mine was OK, but another year I think it would’ve been too thin to repair. I suspect many don’t realise how bad their problem is!

 

[Greeny.]

It’s actually wasn’t that bad to be fair, I have done a couple of these now. Was very solid behind. Big problem is the little strip beween the opening and hinge. Luckily mine was OK, but another year I think it would’ve been too thin to repair. I suspect many don’t realise how bad their problem is!

Fair enough, this was mine pre-treatment obviously, average I would say?

 

[frayz]

Id say that's a bloody good one mate

 

[DomP182]

Sadly mine had rust behind the stone chip that had caused a 10mm hole the top of the inner arch above the filler, where Russ has rust on his. I treated it and whacked some body filler over it then have spent the next year trying to erase my memory of it.

 

[Pegasaurus Rex]

What was the inner arch like? I’d say yours looks pretty damn good!!

 

[Bankrupt_drunk]

Another good job,you two should start up a business refurbishing petrol caps,there must be 1000s want doing.

Agree, good job. I"m tempted to have a look at mine to see what's going on.

 

[DomP182]

I wonder if cutting an copy of the filler hole out and bonding it to the backside with seam sealer before spraying it up would add some needed rigidity?

 

[Pegasaurus Rex]

I would genuinely encourage anyone that gives a s**t about their clio to remove the fuel flap and have a proper good look, especially in the wheel arch area.

 

[DomP182]

I would genuinely encourage anyone that gives a s**t about their clio to remove the fuel flap and have a proper good look, especially in the wheel arch area.

Definitely, there's some horrors hiding under the rear ends

 

[Pegasaurus Rex]

Definitely, there's some horrors hiding under the rear ends

Absolutely 100% agree! It’s why im collecting all the parts so I can tackle it over a week (paternity leave sorted) but there are so many crappy areas under the rear end of the car! It’s a complete s**t show!

it’s funny you can really see a number of these cars getting to the point of non economic repair soon enough.

 

[DomP182]

Absolutely 100% agree! It’s why im collecting all the parts so I can tackle it over a week (paternity leave sorted) but there are so many crappy areas under the rear end of the car! It’s a complete s**t show!

it’s funny you can really see a number of these cars getting to the point of non economic repair soon enough.

😂paternity leave, that's going to go down well!

Pretty sure mine was uneconomical from the start, sure is now but I'm not stopping 😁

 

[Greeny.]

What was the inner arch like? I’d say yours looks pretty damn good!!

Looking tomorrow 👍