I took the time today to treat my Copen to a bit of rust prevention. I've gone with Dinitrol products. Available from here; http://www.frost.co.uk/automotive-rust-products/dinitrol-rust-prevention.html 2 x S330 Dinitrol Cavity wax - for in the sills & inside the rear arches. 1 x Extension hose. 3 x S335 Dinitrol underbody wax - for the rear inside arches & floor plan. I also bought a tin of Hammerite Black Smooth from Halfords. First job, give the underside a good jet wash. Use a stiff brush to clean any mud off. Let it dry. On a flat solid surface jack the car up & support with axle stands. Make sure you loosen off the wheel nuts first. Take off the wheels & remove the front wheel liners. The clips that hold them on arn't too hard to remove. I also removed the front grill & bumper. Once you have the wheel arch liners off, finding all the securing bolts & screws that hold the bumper on isn't too hard. One bolt is hidden behind the number plate. Don't forget to disconnect the spots & indicators. Things don't look too bad. I gave all the surfaces a good coating of S335 Dinitrol underbody wax. I also painted the underside of the front chassis arm with the Black Hammerite. I also painted the metal strap that goes infront of the intercooler. I didn't take any photos of the underside of the body, but I gave that a good coating with the S335 Dinitrol underbody wax. Don't get any on the exhaust though. I didn't get do the rear arches yet. I'll add photos once I've done them. When you re-fit the bumper, don't forget to re-connect all the spots & indicators. Next is to do inside the rear arches & sills. In the front wheel arch, at the front of the lower sill, you'll find a square hole (just above the round plastic bung). This is perfect to feed the extension tube to the S330 Dinitrol Cavity wax. Before you spray any of this, if you've parked on your drive, protect your floor with plastic sheets. The wax will find it's way out of the holes in the sills & drip all over the floor. If you not bothered about marking the floor, don't worry. Push the extension pipe as far in as it will go & begin spraying. Slowly pull the hose back out.
Next is to get at the rear arches. In the boot, along the side of the opening where the hinge mechanism is, you'll find two open holes behind the carpet. You may need to pop out some of the clips. To remove them push the centre dot in a bit. The clip should then be free to pull out. You'll be able to feed the extension hose into these holes. Make sure the rear quater windows are not lowered. Again give a good long spray. The cavity wax will run down to the rear end of the sill. I still need to inside the doors, again I'll add photos when I've done them.
Here's the cavity wax with the extension hose. Here's what I did to protect the doors. The method of taking the door card is covered elsewhere. Be careful removing the plastic cover. The black sealant is very sticky & the cover rips easily. Make sure the window is up. Put the extension hose in the door & start spraying. Again watch where your doing this as it goes all over the floor. To make life easier next time I wouldn't bother taking the door card off. I would just put the hose inside the door using these drain holes.
Another tip for treating the doors. Be careful not to get any cavity wax in the window runners. Once the wax dries it will make the windows squeak as they go up & down. I found this out yesturday. Simple solution though, just spray some silicone oil or WD40 into the runner.
Really excellent posts!!! Thanks for taking the trouble to share all this good experience with us. I will do this to my Copen before the winter. M.
Mr BF restores old Triumphs and swears by Dinitrol products. He has already pencilled the little Hairdryer (as he calls it) in to have its cavities and underside treated.
I didnt realise there was a rust problem with them - i havent even got the tiniest piece of rust anywhere, and it has never been kept in a garage, always in the elements, winter and summer. where do they rust exactly? Ive had it checked and in 6 years, never found any yet
Hi dwayner, It's all down to luck & how well Daihatsu sealed the inner & outer skins of the rear arches. Check the top edge of the rear arch. Where it meets the rear bumper. Also the leading edges of the sills just behind the front wheels
Did my Copen over the Easter break - front, rear, sills and doors with Waxoyl. The rear archer from inside the boot took loads - think I may have filled the cavity completely!? Worth the effect - here's to a rust free Copen!
Finally got around to finishing off the rust protection. I bought a couple more cans of Dinitrol underseal. Taking the bumper off was quite easy. Jacking the car up is a bit of an issue. With my Jack I couldn't lift it high enough to get the axle stands under. So I used the Jack from the boot as a back up. Once the wheels were off I gave the arches a could scrub with a stiff brush to get the worst of the dirt off. Then gave it a quick wash. Left it to dry. Then applied the underseal. Just don't get any on the exhaust.
Once again, Adam, thanks from all of the community for the terrific pics and advice you've put up on this critical issue. One question: I recently visited Sharoe Green Garage in Preston (Daihatsu dealer) who originally supplied my car. They very kindly carried out some warranty work FOC - 4 new alloys! - and we had a discussion about rust-proofing on the post-2007 models. They told me that Daihatsu did a better job of protecting the 1.3s. However, I would be really interested to know whether this is borne out by members' experiences (although, of course, it's a newer vehicle and has had less time to rust). Do I need to do the full course of treatment on Neville (2009) that you've done here, or have Daihatsu done their job? I'd be interested in your experience/knowledge on this one ... or anyone else's for that matter. Thanks!
My attempt at rust prevention of my rear...and the car. Partially done. Have to wax the lower part and behind there, the rear of the wheel arch where the plastic panel covers. Not sure I'm going to cover as much of the arch as Adam did. So this will be the lighter weight sports rust prevention mod. the main rust was at the bottom edge, just above and to the outside of the tailpipes. You might just be able to see my brown staining in the first photo. Alternatively you can look at a photo of my car for rust. Also one of the clip holes was bubbling so I got a trusty screw driver to it and removed it how the professionals do. You can see the main patches in lower photos where I did some undercoat. I then added some silver paint over. Not copen silver, but know one will see it and it will be covered in brown wax also. It has a quick splash of clear coat too, to seal it from moisture. it wasn't a professional attempt at paint, more just a protection coating. I primed, colour coat and clear coat in about an hour! Couldn't wait hour or so for each coat as it was 7 or 8 in the evening. There is a plug in the rear end of the sill which I took out to poked my extension nozzle in, like Adam did at the front end, to squirt some wax in there. I had already done the sills last year but from holes near the door. Took this opportunity to make sure. There are also plastic plugs on the very rear at the side that I squirted some more between the sheets. I also stuck the nozzle in the bolt holes as there is cavity behind them. It might not be thorough, but better than nothing.
