Paulfc Posted September 14, 2018 Report Share Posted September 14, 2018 Hi, I've just spent a really 'wonderful' week or so ? removing bitumen underseal and the attached 'sound deadening felt' ?? felt from the entire underside of the bonnet and now have it back to bare metal and, of course, associated areas of rust all of which, fortuneately, are treatable. The reason I removed it was it looked awful and I want the bonnet underside to look 'smart' and also so I could see what the underseal was hiding. Leaving aside what I've found which will cost me to fix, I'm in a quandary as to what to now do with the bonnet underside. I'm leaning towards spraying it with stone chip and then over coating it with a colour to match the external colour. I'm not sure this is the best thing to do and would appreciate any views/opinions, product recommendations etc. from anyone out there who's had a similar challenge and come up with a solution. Also, if I do use stone chip paint would I use a conventional primer under it? I'll be grateful for any advice, thanks, Paul Link to comment Share on other sites More sharing options...
Colin Lindsay Posted September 14, 2018 Report Share Posted September 14, 2018 If it's stonechip primer then anything else is unnecessary, unless you're applying a good rustproofing to the metal first then stonechip over that. I'd just paint the underside the same as the topside, but stonechip the wheelarches. Link to comment Share on other sites More sharing options...
Gully Posted September 14, 2018 Report Share Posted September 14, 2018 The underside of my bonnet is stonechip then body colour. Gully Link to comment Share on other sites More sharing options...
Paulfc Posted September 14, 2018 Author Report Share Posted September 14, 2018 Thanks guys. Gully could you post a picture please? Link to comment Share on other sites More sharing options...
wayne Rollinson Posted September 14, 2018 Report Share Posted September 14, 2018 I will be doing etch prime stone chip then colour match with 2k on the underside of the full body arches and bonnet, unless i end up with a gt6 fibreglass one, unless people think there is a better way, regards wayne. Link to comment Share on other sites More sharing options...
Nick Jones Posted September 15, 2018 Report Share Posted September 15, 2018 Why the stonechip? Apart from the wheel facing side of the wheel tubs the rest doesn't see any particular violence. Etch primer, primer, then body colour is what it would have had originally. Just in the painful process of scraping bitumen based under seal off the inside of my GT6 bonnet. Deeply unfun...... Nick Link to comment Share on other sites More sharing options...
daverclasper Posted September 15, 2018 Report Share Posted September 15, 2018 I don't understand why some folk, under seal the whole underneath of bonnet, not like it's a rust trap. Maybe sound deadening?. Dave Link to comment Share on other sites More sharing options...
Paulfc Posted September 15, 2018 Author Report Share Posted September 15, 2018 Nick, I found that covering the underseal with a paint stripper (STRIP AWAY PRO) and leaving it for 20 minutes, working it in and then applying again if necessary depending on the thickness of the u/s worked well. Strip Away Pro is aggressive so you have take care - cover up, wear gloves, if it gets on skin rinse under water and protect eyes etc. and protect any part of the car you don't want to strip the paint off. Horrible really unpleasant job but satisfying when you get it done. You can get it from firms who specialise in supplying the "car refinishing trade". Paul Link to comment Share on other sites More sharing options...
Badwolf Posted September 17, 2018 Report Share Posted September 17, 2018 Saw a car yesterday with a large area of the underside of the bonnet covered in silentcoat. The rest was match painted to the body colour. The silentcoat cut down bonnet vibration/noise etc and protected from stones, heat etc. Best of all worlds for me. Link to comment Share on other sites More sharing options...
Gully Posted September 17, 2018 Report Share Posted September 17, 2018 On 14 September 2018 at 8:43 PM, Paulfc said: Thanks guys. Gully could you post a picture please? Sorry - missed this. Will do so over the next day or so when I next see the car in the daylight! Gully Link to comment Share on other sites More sharing options...
Unkel Kunkel Posted September 17, 2018 Report Share Posted September 17, 2018 On 9/15/2018 at 7:21 PM, Paulfc said: Nick, I found that covering the underseal with a paint stripper (STRIP AWAY PRO) and leaving it for 20 minutes, working it in and then applying again if necessary depending on the thickness of the u/s worked well. Strip Away Pro is aggressive so you have take care - cover up, wear gloves, if it gets on skin rinse under water and protect eyes etc. and protect any part of the car you don't want to strip the paint off. Horrible really unpleasant job but satisfying when you get it done. You can get it from firms who specialise in supplying the "car refinishing trade". Paul I think this is a dichloromethane aka methylene dichoride based paint stripper -the ingredient that is so effective but no longer to be found in of the paint stripers in the DIY places like B&Q.(Nitromors and others are pretty ineffective these days as they boast they are now dichloromethane -free ). However, I reiterate your very sensible advice to be careful, Paul. -and feel I must add : - Only ever use this in a really WELL-VENTILATED place - ie outdoors. Apart from being very readily absorbed through skin contact , it is easily breathed in. It really can cause short term (drowsiness ,dizziness, headache) for hours or days and longer term neurological problem with peripheral nerve problems in addition to liver dysfunction . Also - (and this may at first seem bizarre) but it can cause carbon monoxide poisoning as it is metabolised to CO. = Cover up - and use it outdoors. Link to comment Share on other sites More sharing options...
Clive Posted September 18, 2018 Report Share Posted September 18, 2018 I am with Nick on this. Stonechip the wheel arches, the rest just paint. I am not a fan of under-bonnet soundproofing, it seems to get very tatty very quickly, and has few real benefits. Far better to use that sort of stuff inside the car, bulkhead in particular, also treat the gearbox tunnel to something suitable. But, if you want sound deadening on the bonnet, by all means give it a go. Pay attention to reviews on what lasts well though. Link to comment Share on other sites More sharing options...
Paulfc Posted September 18, 2018 Author Report Share Posted September 18, 2018 Thanks to all, especially for the reinteration and extension on the care to be taken when when using "real" paint stripper - it always must be safety first. On reflection I think I'll be going with Nick's suggestion. Paul Link to comment Share on other sites More sharing options...
Clive Posted September 18, 2018 Report Share Posted September 18, 2018 Don't be too afraid of chemicals. The problems happen when people don't pay any attention to safety. I used to use DCM lot in the lab (when I was working in an analytical lab, a lifetime ago) and that was indoors, no special ventilation etc just windows open. If you use it in a garage with the door open you won't have too much of an issue, just keep it off your skin. And a tip, if you use a chemical paintstripper, paint it on a nice layer, and immediately cover with cheapo tinfoil to stop it evaporating. (you can use expensive tinfoil if you insist) Then leave for an hour or so and it should do the business. I recently used some modern "safe" stripper to get 7 layers of paint off some fireplaces. I used the tinfoil method, and left overnight. It worked well....Not sure how effective on car paints though. That was screwfix no-nonsense stripper. But I reckon it needs overnight to work. Link to comment Share on other sites More sharing options...
Badwolf Posted September 18, 2018 Report Share Posted September 18, 2018 I have got a 5 litre bottle of Starchem Synstrip, which has been highly recommended. Came off fleabay (current item number 201464152727) about £26.45 inc carriage or cheaper if you wait 'til a sitewide dicoount day-I got an extra 10%off. It contains dichloromethene and phenol. Supposed to be for trade use only and carries all the usual warnings. I agree with Clive. Treat it as a dangerous substance as you would neat bleach and take all the appropriate precautions including disposing of the waste, even though it is supposed to be water soluable. Also recommended to score the old paint to allow penetration...like the tin foil idea too. Link to comment Share on other sites More sharing options...
Paulfc Posted October 9, 2018 Author Report Share Posted October 9, 2018 The last panel I have to deal with is the near side lower wing. It's not original and still has the part label on it - 909663 DEC 85. It hasn't got underseal on it but some sort of waxoil type coating. When I take the coating off the finish is black and obviously the original panel inner finish and it's in excellent condition. Can anyone please tell me what this coating is as it's impervious to paint stripper and also can I, after I've cleaned it up, just apply a primer and top coat without taking it back to bare metal first? Thanks Link to comment Share on other sites More sharing options...
Adrian Posted October 9, 2018 Report Share Posted October 9, 2018 I did exactly as suggested, last year. Hot air gun and scraper to remove under seal and a wash down with white spirit to dissolve the last bit from surfaces prior to prep for por 15. Then undercoated (should have used their tie coat as difficult to get the cured stuff scuffed enough on all the supports etc). Then stone chip in wheel arches only. Body colour over all and dinatrol clear wax in arches. Hate underseal - I caught it in time but it had already started to come away in places on the wheel arches and was trapping moisture. Horrible job stripping it away but the results speak for themselves. Good luck! 1 Link to comment Share on other sites More sharing options...
Nick Jones Posted October 9, 2018 Report Share Posted October 9, 2018 Your starting point looks horribly familiar - exactly what mine looks like...... except mine (was) alot rustier around the edges. Now you've perfected the technique, would you like to do another....? ? Nick Link to comment Share on other sites More sharing options...
Adrian Posted October 9, 2018 Report Share Posted October 9, 2018 Sadly I’m just starting to do the same on the underside of the mini (but it is brittle so cold scraping seems to work). word of warning watch out for too much and regular flexing of the bonnet whilst cleaning off so you don’t strain the hinges Link to comment Share on other sites More sharing options...
Clive Posted October 10, 2018 Report Share Posted October 10, 2018 10 hours ago, Paulfc said: The last panel I have to deal with is the near side lower wing. It's not original and still has the part label on it - 909663 DEC 85. It hasn't got underseal on it but some sort of waxoil type coating. When I take the coating off the finish is black and obviously the original panel inner finish and it's in excellent condition. Can anyone please tell me what this coating is as it's impervious to paint stripper and also can I, after I've cleaned it up, just apply a primer and top coat without taking it back to bare metal first? Thanks Which paint stripper? Anyway, it is their magic primer stuff. Either sticks like yours or flakes off. So a good rub with abrasive to remove anything that is not well attached, then primer etc. Incidentally, when I attacked my Vitesse chassis (crikey that was 24 years ago!) I used a wire wheel in a grinder. Not much resists. However, the initial primer on the chassis was unbelievable. I was going to take it to bare metal, but gave up (except for the odd dodgy area) as it was way better than anything else I could have put on there. I just etched bare areas, then primed, stonechipped and topcoated. Sadly the chassis expired 13 years later. The waxoil I had liberally applied to the insides didn't do its job. Hence I don't use that any more,but recommend the dinitrol stuff. One is specific for old, potentially surface rusted surfaces. Almost like WD40, but seems to soak right into the surface. Link to comment Share on other sites More sharing options...
Clive Posted October 10, 2018 Report Share Posted October 10, 2018 Another thought.... When I rebuilt my current spit, I rolled the tub on its side and attacked the underside with wire wheel on a grinder. Seemed to take days (in all honesty you can't do it all day, I think hands would suffer from the vibration from the grinder, a serious issue)and filthy work. Anyway, after I had done all that, a mate popped down and talked about cleaning forklift trucks that had been on site fro several years. A grubby job. Anyway, he uses a diesel steam cleaner. And reckons it will strip good factory paint of even new equipment if you don't take care. So I was wondering if a proper steam cleaner (not a domestic pressure washer) could be used to remove underseal and anything else. Should be OK on sound panels. It would save a great deal of misery, and parts would be clean ready to start on the nicer stuff. Link to comment Share on other sites More sharing options...
Paulfc Posted October 10, 2018 Author Report Share Posted October 10, 2018 Adrian, You've got that bonnet looking good, I hope I can get somewhere near with mine. Are you using a compressor or cans? Also, in your 4th pic. the lateral strengthening bar - what are the two oblong box sections (just inboard of the wheel arch supports) with the threaded captive nuts on the inside for? Clive, Thanks for the response/advice. The paint stripper I use is Strip Away Pro which I find excellent. Paul Link to comment Share on other sites More sharing options...
Adrian Posted October 10, 2018 Report Share Posted October 10, 2018 I used rattle cans. As for the box section I honestly don’t know, nothing was attached prior to stripping. Link to comment Share on other sites More sharing options...
Gully Posted October 11, 2018 Report Share Posted October 11, 2018 On 10 October 2018 at 15:52, Paulfc said: Adrian, what are the two oblong box sections (just inboard of the wheel arch supports) with the threaded captive nuts on the inside for? Paul Do you mean the plates for the bonnet locating cones? Struggling to see anything else matching the description! They thread up into the plate and the lock nut goes up against the plate to hold them and allow adjustment. Gully Link to comment Share on other sites More sharing options...
Paulfc Posted October 12, 2018 Author Report Share Posted October 12, 2018 Hi Gully, No. See the attached image highlighting the subject of the question. Hopefully I've got the image attached. Paul strengthener.pptx Link to comment Share on other sites More sharing options...
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