Paddy_SP Posted October 28, 2007 Share Posted October 28, 2007 Hi All - This is my first post on here, so I thought I'd start with a techie question! I'm currently rebuilding a '93 Defender 110 CSW with a new Richards galvanised chassis, and want to do everything I can to ensure it lasts as long as possible. One of the first things I did after thoroughly examining it was liberally coat it with industrial zinc spray paint. This is because I could see that the hot-dip process hadn't reached into all the nooks and crannies hidden away in the many recesses. I should say that I am an absolute obsessive about such things, so it's not a criticism of the product - no-one could afford to employ someone to clean the metalwork to the necessary levels and remain in business... Anyway, my question is this - I have a large quantity of fire-grade aerosol expanding foam, and am wondering whether I should use it to completely fill the chassis before I go bolting the rest of the vehicle onto it. I can see that if I ever needed to weld anything to it, the foam would be a real pain. On the other hand, it would be an excellent way of waterproofing it... Any constructive comments would be most appreciated! Quote Link to comment Share on other sites More sharing options...
need4speed Posted October 28, 2007 Share Posted October 28, 2007 'This is because I could see that the hot-dip process hadn't reached into all the nooks and crannies hidden away in the many recesses.....' I may be wrong (not unknown) but are the chassis not completely submerged in a zinc bath? If so, there is no reason why every single nook and cranny shouldnt be completely galvanised.... Quote Link to comment Share on other sites More sharing options...
western Posted October 28, 2007 Share Posted October 28, 2007 Only downside would be if the expanding foam isn't fully waterproof & you've already mentioned the possible problems off welding repair plates on in the future, if it was my new chassis I'd have it hot dipped [totally immersed]galvanished, can't see then that it wouldn't get into all the unseen places within the chassis. Quote Link to comment Share on other sites More sharing options...
need4speed Posted October 28, 2007 Share Posted October 28, 2007 It was a brand new chassis from Richards Chassis, so surely it has been completely immersed??? Quote Link to comment Share on other sites More sharing options...
Paddy_SP Posted October 28, 2007 Author Share Posted October 28, 2007 It was a brand new chassis from Richards Chassis, so surely it has been completely immersed??? I should have said that the galvanising was only missing where dirt had accumulated in the seams of some of the joins. The chap who delivered it said it had been completely immersed in a hot-dip bath - this is borne out by the fact that the zinc is in place on the insides of the box sections. I just couldn't bear to see any rust starting to show... Quote Link to comment Share on other sites More sharing options...
RobotMan Posted October 28, 2007 Share Posted October 28, 2007 What happens after a few years of salt and frost etc and it starts to break loose into big rattling chunks that you can't get out? Quote Link to comment Share on other sites More sharing options...
Happyoldgit Posted October 28, 2007 Share Posted October 28, 2007 have a read of this Quote Link to comment Share on other sites More sharing options...
Paddy_SP Posted October 28, 2007 Author Share Posted October 28, 2007 have a read of this Many thanks for that - I must admit that trapped moisture was my main concern. It looks like I'll be going back to go 'ol Waxoyl then! Quote Link to comment Share on other sites More sharing options...
Guest diesel_jim Posted October 28, 2007 Share Posted October 28, 2007 And remember that the main rear wiring harness goes down through the chassis as well, so if you sprayed that lot in before you pulled the cable through, you'd have a mess. Also, if the cable did develop a problem whilst sealed in... again, messy. Quote Link to comment Share on other sites More sharing options...
Paddy_SP Posted October 28, 2007 Author Share Posted October 28, 2007 And remember that the main rear wiring harness goes down through the chassis as well, so if you sprayed that lot in before you pulled the cable through, you'd have a mess.Also, if the cable did develop a problem whilst sealed in... again, messy. Another thing I should've said is that I was planning to run the cables outside the chassis - expanding foam and electrics is a good recipe for a fire as the wires don't get a chance to cool down... Quote Link to comment Share on other sites More sharing options...
gruntus Posted October 28, 2007 Share Posted October 28, 2007 Another thing I should've said is that I was planning to run the cables outside the chassis - expanding foam and electrics is a good recipe for a fire as the wires don't get a chance to cool down... Hi Paddy, I would work on being less obsessive!! First off a standard chassis should last an age, a galvanised one will outlast most people and lets face it you probably won't keep it more than ten years! I have a 1993 Audi 80 with 206,000 miles on the clock that is zinc phosphate coated (not a hot zinc bath) and it is still rust free. The measures you are taking are little overboard! If you do decide to run the cabling in the chassis make sure you place all the wires in copex tubing or the like (plastic tube for running electrical systems in) as there may be a few sharps from the galv inside. The alternative is to P clip the copex to the chassis. With regard to cables heating up this should never happen if the cabling is the correct size for the current it was designed to carry. Cabling shouldn't heat up and cool down!!! I know that this can happen in the case where starter motor cables are hammered for a while or poor earths can also cause this but this is usually on high current devices that this will happen. Use your rebuild as a calming, therapeutic, Zen like project that can help reduce your OCD! All the best and I look forward to some piccies!! Cheers Grant Quote Link to comment Share on other sites More sharing options...
RobotMan Posted October 28, 2007 Share Posted October 28, 2007 With regard to cables heating up this should never happen if the cabling is the correct size for the current it was designed to carry. Cabling shouldn't heat up and cool down!!! I think you'll find that to be wrong. The correct cable for a given current is based on many factors including the enclosure or trunking that carries it. If you take a look in the 16th edition you'll find lots of tables covering correction factors for things that affect the heat dissipation of the cables for a given amperage. The concept applies equally to vehicle electrics even though the regulations don't. Quote Link to comment Share on other sites More sharing options...
nick w Posted October 28, 2007 Share Posted October 28, 2007 Hi All - This is my first post on here, so I thought I'd start with a techie question! I'm currently rebuilding a '93 Defender 110 CSW with a new Richards galvanised chassis, and want to do everything I can to ensure it lasts as long as possible. One of the first things I did after thoroughly examining it was liberally coat it with industrial zinc spray paint. This is because I could see that the hot-dip process hadn't reached into all the nooks and crannies hidden away in the many recesses. I should say that I am an absolute obsessive about such things, so it's not a criticism of the product - no-one could afford to employ someone to clean the metalwork to the necessary levels and remain in business... Anyway, my question is this - I have a large quantity of fire-grade aerosol expanding foam, and am wondering whether I should use it to completely fill the chassis before I go bolting the rest of the vehicle onto it. I can see that if I ever needed to weld anything to it, the foam would be a real pain. On the other hand, it would be an excellent way of waterproofing it... Any constructive comments would be most appreciated! being in the building trade i have seen many differint uses of ex foam and i can confirm it holds moisture ,kind of like a sponge really and also causes condensation by its properties of insulation good idea but may cause more problems than cures as already expressed a galv chassis should be dipped therefore covering all parts Quote Link to comment Share on other sites More sharing options...
nick w Posted October 28, 2007 Share Posted October 28, 2007 I think you'll find that to be wrong. The correct cable for a given current is based on many factors including the enclosure or trunking that carries it. If you take a look in the 16th edition you'll find lots of tables covering correction factors for things that affect the heat dissipation of the cables for a given amperage. The concept applies equally to vehicle electrics even though the regulations don't. dont forget to apply diversity too Quote Link to comment Share on other sites More sharing options...
Paddy_SP Posted October 28, 2007 Author Share Posted October 28, 2007 Hi Paddy,I would work on being less obsessive!! Use your rebuild as a calming, therapeutic, Zen like project that can help reduce your OCD! All the best and I look forward to some piccies!! Cheers Grant Thanks for all the helpful input chaps! As for 'I would work on being less obsessive!! ' - I've been trying that for 47 years with no success... My good lady says that I'm not normal. To give you an idea of how 'not normal' I am, check out my little hillclimb racer - it has a one gallon fuel tank and does 3mpg... My Little Racer Quote Link to comment Share on other sites More sharing options...
Shox Dr Posted October 28, 2007 Share Posted October 28, 2007 Thanks for all the helpful input chaps! As for 'I would work on being less obsessive!! ' - I've been trying that for 47 years with no success... My good lady says that I'm not normal. To give you an idea of how 'not normal' I am, check out my little hillclimb racer - it has a one gallon fuel tank and does 3mpg... My Little Racer Sweet Harley, a bit different to the Fatboy I have in the shed waiting on an Edelbrock 1550 kit. should give me 120+ for both BHP & Torque As for the chassis. I went a different route, i bought a new OEM chassis and then plated the x-member, dumb irons and outriggers, and then welded up all the holes, leaving the larger loom holes to inject waxoly I then riveted a plate over the hole so I could inspect if needed in the future. I've pressure tested it and it's totally sealed. 5 Coats of Micaceous Iron Oxide, 4 Coats of Stone chip and then Dinol'd Quote Link to comment Share on other sites More sharing options...
Shox Dr Posted October 28, 2007 Share Posted October 28, 2007 i don't intend on doing anymore repairs for a long long long time Quote Link to comment Share on other sites More sharing options...
RobotMan Posted October 28, 2007 Share Posted October 28, 2007 My chassis is like a pair of great escape trousers, it's always filling up with mud and bringing it home. Nothing wrong with having a few hundred pounds of mud packed into a galv chassis it helps with stability, honest. Quote Link to comment Share on other sites More sharing options...
gruntus Posted October 28, 2007 Share Posted October 28, 2007 I think you'll find that to be wrong. The correct cable for a given current is based on many factors including the enclosure or trunking that carries it. If you take a look in the 16th edition you'll find lots of tables covering correction factors for things that affect the heat dissipation of the cables for a given amperage. The concept applies equally to vehicle electrics even though the regulations don't. Hi Rob, Lets stay a little objective, we are talking after all of lighting and a heated rear screen! Cheers, G Quote Link to comment Share on other sites More sharing options...
Paddy_SP Posted October 28, 2007 Author Share Posted October 28, 2007 Sweet Harley, a bit different to the Fatboy I have in the shed waiting on an Edelbrock 1550 kit. should give me 120+ for both BHP & Torque As for the chassis. I went a different route, i bought a new OEM chassis and then plated the x-member, dumb irons and outriggers, and then welded up all the holes, leaving the larger loom holes to inject waxoly I then riveted a plate over the hole so I could inspect if needed in the future. I've pressure tested it and it's totally sealed. 5 Coats of Micaceous Iron Oxide, 4 Coats of Stone chip and then Dinol'd The 1550 kit for your Harley sounds good! As for your chassis - it sounds as though you have a similar approach to me - the photos you posted look great! Quote Link to comment Share on other sites More sharing options...
mike4444244 Posted October 28, 2007 Share Posted October 28, 2007 that bike is an absolute masterpiece! btw i'll echo all of above about the foam.... dont do it! mike Quote Link to comment Share on other sites More sharing options...
Paddy_SP Posted October 29, 2007 Author Share Posted October 29, 2007 that bike is an absolute masterpiece! btw i'll echo all of above about the foam.... dont do it!mike I thank you, Kind Sir! Please don't worry about the foam idea, I've moved on from that - I thought I'd explore the wide-ranging expertise of the site's members before rejecting it out of hand, & now have some excellent reasons not to use it! Quote Link to comment Share on other sites More sharing options...
q-rover Posted October 29, 2007 Share Posted October 29, 2007 If you want to paint your chassis, then don't bother with Hammer****e or similar. Go to a good paint supplier (not B&Q) and get some proper industrial paint. Preferably designed fo roffshore use... Quote Link to comment Share on other sites More sharing options...
Guest diesel_jim Posted October 29, 2007 Share Posted October 29, 2007 If you want to paint your chassis, then don't bother with Hammer****e or similar.Go to a good paint supplier (not B&Q) and get some proper industrial paint. Preferably designed fo roffshore use... I bought some of Wickes's "direct to metal" paint, basically a hammer$hite rip off, but it dries looking almost nylon/plasticy, and seems a lot more durable and less brittle. and about 1/4 of the price too! Quote Link to comment Share on other sites More sharing options...
Paddy_SP Posted October 29, 2007 Author Share Posted October 29, 2007 I bought some of Wickes's "direct to metal" paint, basically a hammer$hite rip off, but it dries looking almost nylon/plasticy, and seems a lot more durable and less brittle.and about 1/4 of the price too! I've used that before - it's bl00dy good, isn't it! Quote Link to comment Share on other sites More sharing options...
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