Original finish to under side or car

[pugfrank 14 1 Cars]

Hi all, 

 

In the process of striping all the old underseal from under the boot area and rear beam.  What a job......! Can anyone tell me whets the best product to apply back to these tight areas between wheel arch and underside?  

 

For the main areas my plan was Epoxy primer/paint followed by a few couple of coats of UPOL Gravitex, but I can't see how Im going to be able to spray the Gravitex evenly into these small tight spaces, to give good coverage and maximum protection. 

 

The finish from factory is very thick but very uneven in these places. 

 

Is it seam sealer that has been but on with a brush in these areas on the second photo it looks a bit like this. 

 

With the Gravitex should I be finishing it with any after or can it be left as is?  Is it a question of the more layers you put on the more protection! of is the Gravitex sufficient on its own? 

 

Thanks for your help in advance. 

 

 

[pugfrank 14 1 Cars]

Started to strip the underside in the above areas.  First car I have ever done, and cant believe how mush seam sealer is in these areas.  Is this the norm? 

 

 

[DamirGTI 342]

Yes , it is a bit heavily coated with underseal ... it's easier to remove by heating it up with an hot air gun , it'll soften it then you can scrape it off  .

But best done outside or in well ventilated garage as the stuff stinks like *** once heated/at burning point .

 

However , do not get cared away too much ... removing all the OE applied underseal , the OE stuff is really good and you yourself wont be able to protect the metal by re-applying new/fresh underseal as good as it was done by the factory when the shell was new , freshly electroplated , dry etc.

 

Remove only on areas where you actually see the rust , loose/lifted/broken/scuffed down to the metal parts of the underseal . The rest which is

sound - leave it be .

Also , take care not to scratch too much the black areas on the floor panels underneath the underseal - that's electroplated rust proofing coating .

 

D

Edited October 16, 2021 by DamirGTI

[pugfrank 14 1 Cars]

Thanks D, I've screwed up here then as black coating is all scratched up now, and I've removed way past the rust spots, stripping off loads of underseal! Doh s**t. 

[pugfrank 14 1 Cars]

Any tips on how to apply the underseal back in these area's, nice and thick push in with a paintbrush? 

[DamirGTI 342]

There's brushable seam sealer , which you can use to protect those areas thick kinda like factory ... but problem with ordinary seam sealers (cheaper ones especially) , is they tend to sag/wrinkle after a while ...

 

Thus , i'd recommend instead non hardening PU (polyurethane) sealant in tube/cartridge (apply with cartridge gun and spread around with plastic spatula) ... when applied it never drys off hard/solid , always stays kinda soft/rubbery and doesn't sag/wrinkle , and can be painted over . Bonds on well/strong onto the surface (prep surface free from moisture/dust etc.) , which is what you want .

 

There's one very good PU sealant in cartridge made by "Dinitrol" , thick gooey yellow stuff very similar to that of the OE underseal on a 205 , cannot remember product code .. but do some research on Dinitrol website . 

It's commonly used by the OEM makes/models when building up the shells on factory assembly lines ... Dinitrol - very good quality chemical products , recommend .

 

Next option would be - "Henkel/Teroson" , also used by the OEM , very good quality .

 

D

Edited October 16, 2021 by DamirGTI

[pugfrank 14 1 Cars]

Thanks D, will have a read up. 

[DanteICE 72]

The henkel/teroson stuff I think is this stuff:

 

 

[DanteICE 72]

[pugfrank 14 1 Cars]

Thanks Geoff, are there more pages to this document? Its still confusing me to what I need to reapply to these areas to restore best protection. 

 

The scraping and cleaning of the underside is snow balling! maybe this is not a surprise to some of you but this is the first car I have done.   

 

Its really surprising me how thick the factory product has been applied in these areas.  Junction between floor pan, rear sill and rear arches, its been laid on so thick, its taking ages to chip off original finish and proving impossible not to scrape the black finish.  Even in areas were there seems to be no visible signs of cracking and peeling Im finding little areas of light surface rust,  so all I seem to be doing is striping more and more off to make sure I don't find any more. 

 

Its also now really concerning me how Im going to Diy apply suitable products back in these areas.  As I agree with the above comments that Im never going to be able to replicate the factory finish and protection!!  

 

I want to be doing the job right and once if I can.

 

 

 

 

[Richard309Sri XU5JA 205GTi 8]

been following your thread/also found a thread from another website for my 309,initially looking for something else(engines)but scrolling through that then found that he re-did the entire underside of the boot area - wheel arches etc.looks similar to 205 so might be useful. 

 

thought it might be useful you could see what he did. (I am not spamming for another website ) just seemed to be a lot of similar areas. Also gives some more ideas of good products to use. 

 

https://www.detailingworld.co.uk/forum/showthread.php?t=372040&page=30

 

regret to say I'm not the expert but would like to learn more about it also. These posts above are great on this thread - really interesting to read - wanted to add anything I can. 

3 hours ago, pugfrank said:

Its still confusing me to what I need to reapply to these areas to restore best protection.

he seems to mention deox gel and also zinc primers? I can see how Zinc primer would be good 

Bilt hammer doex gel 

 

Reading and looking at his thread yes seems normal you would be finding more than first appeared. 

 

also I did search 205gti drivers site and found this - could this also be useful? 

 

 

https://www.hbbody.com.gr/

 

think that is what he used. 

3 hours ago, pugfrank said:

Its also now really concerning me how Im going to Diy apply suitable products back in these areas.

need a compressor and a air spray gun minimum? 

 

I'll need to read these also this afternoon then Ill have a better idea myself. 

[pugfrank 14 1 Cars]

Thanks Richard309Sri XU5JA

 

What a great read from the Detailing World Forum, gives me some reassurance that what and how im doing things is on the right path.   

 

I too have done a lot of online reading and found many different opinions on best products to apply.  After removing as much rust as possible with a powed tooled wire brush and scraper I have settled on a system of two good coats of Bilt Hamber Hydrate 80, followed buy a coat of 2part epoxy primer, followed buy a coat of Upol Graitex. (I have a small compressor and purchased a application gun)

I have picked up some tubes of PU seam sealer for recovering the panel joins and seams.

 

One area Im still unsure of how Im going to protect is the seams as highlighted, perhaps a rally really small bead of Seam sealer lightly pushed and shaped with my finger! The trouble is the seams that join only form an area a couple of millimetres wide. 

 

 

This is currently the areas I have cleaned and prepared so far with 1 coat of BiltHamber Hydrate 80.

  

 

 

 

 

[DanteICE 72]

6 hours ago, pugfrank said:

Thanks Geoff, are there more pages to this document?

Erm, nothing in terms of underside coating, there's stuff on dimension, what plastics were used for the bumper etc, and how some panels are precoated steal. Nothing that'd be useful to you for this job, I reckon.

Edited October 19, 2021 by DanteICE

[pugfrank 14 1 Cars]

10 minutes ago, DanteICE said:

Erm, nothing in terms of underside coating, there's stuff on dimension, what plastics were used for the bumper etc, and how some panels are precoated steal. Nothing that'd be useful to you for this job, I reckon.

Ok thanks Geoff.