Practical Wiring - Professional Motorsport: Step 9 - Transition and Connector Boot Recovery and Sealing
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Step 9 - Transition and Connector Boot Recovery and Sealing
26.00
| 00:00 | - The ninth step of the HPA 10 step professional motorsport harness construction process is that of recovering all of our transition point sealing boots into place, our connector body sealing boots into place and our labelling materials onto the harness as well. |
| 00:16 | This is where the harness is going to take on its final finished appearance and all those long hours and hard work that you've put in are going to result in a beautiful sealed robust and really quality looking harness. |
| 00:29 | We're going to have a look at the three most common scenarios that you'll strike in detail here. |
| 00:35 | I'm going to look at a Deutsch DTM series connector that we're going to boot with a section of Raychem SCL. |
| 00:42 | We'll look at our transition points here which we'll be booting with our Raychem moulded shapes. |
| 00:48 | In this instance it's a 202K142 for this branch. |
| 00:51 | And then down the other end of our harness we're going to look at a right angle moulded shape for those bulkhead connectors where they meet the bulkhead of our FD3S. |
| 01:00 | You'll see some common themes when we're doing this though in that we are making sure we've got potting compounds in place when we're recovering our boots into place as the aim of what we're really trying to do here is seal up the harness. |
| 01:13 | So any moisture or those road going and road grime conditions that it's going to be exposed to, aren't going to result in any ingress of dirt and grime, and it's gonna keep the harness nice and reliable for its lifespan. |
| 01:26 | Now as I mentioned, the first example we're going to have a look at here, is a Deutsch DTM2 pin plug right on the end of our harness here so it's actually nice and easy to work with on the bench and show you what we're doing. |
| 01:37 | This is actually our knock sensor branch. |
| 01:39 | It's a Deutsch DTM2 pin connector because on the vehicle we'll be potting the knock sensor connector 'cause they are known to be a little bit dodgy in that application. |
| 01:50 | For booting to the back of our DTM connector here, we've used a specific type of DTM connector which has a modification on the back here to take a boot. |
| 01:59 | So this is just a little housing that's ultrasonically welded onto the back of the connector by the factory, it's got a bit of a lip here, and we're just using some SCL to shrink down onto that, gonna give us a nice bit of material there to grab onto that connector body. |
| 02:13 | And with our Raychem DR25 here we've gone ahead and abraded that with our 80 to 120 grit sandpaper all the way around and that's gonna give a nice surface on that DR25 for the potting compound on our SCL here to key into. |
| 02:29 | So to begin the process here I'm just going to get our boot into place on the back of the connector. |
| 02:34 | When I recover this down, I do want to recover it all the way to the base of the connector body here to give us the largest amount of area where that potting compound is going to be gripping onto our connector body. |
| 02:45 | So we'll get that into place there, get our heat gun warming up, and I'm going to have to move the heat gun around while I'm doing this. |
| 02:53 | So we'll try and keep that in shot so you can see what's happening. |
| 03:01 | That boot's recovered down really nicely there 'cause we've got the right size of SCL on there. |
| 03:06 | We can see our potting compound has flowed so we know that's gonna be gripping onto our connector body, making a good connection and the same story on our DR25 here. |
| 03:14 | Just while it's cooling down it's good to hold it in the orientation that you're going to want it to be in its final form. |
| 03:20 | This SCL actually becomes very rigid as it cools and it is going to maintain the orientation that you hold it in while it's cooling down. |
| 03:28 | Now you would have seen while I was recovering that there, I started off with our connector end, and I made sure I got it recovered nicely into the base of the connector there before I actually started moving the heat down onto our DR25. |
| 03:41 | If you start from the other end, you can strike a bit of a tricky situation where you get it locked onto your DR25 and you move the heat up to the connector and you actually find that boot is a little too far towards the end of the connector there and it's not going to recover down very nicely. |
| 03:56 | So to avoid that, I do recommend starting from the base of the connector here and working back towards the harness. |
| 04:01 | And that's going to be the same story for any of these boots that we're recovering into place for this step of our process. |
| 04:08 | Now while I've got this harness section out here, I'm actually gonna go ahead and recover the label into place now as well. |
| 04:14 | So this is our knock sensor connector. |
| 04:16 | And because we were very careful in the earlier steps of the process to get all our labelling materials in place, we've got no worries here, we can just simply slide that down. |
| 04:26 | A good tip to give you harness a really nice professional finished appearance is to keep your labels the same distance from the face of your connectors. |
| 04:35 | Keep that a standard throughout your harness and you'll find it'll give it a really nice finished look. |
| 04:41 | So I find around about, between 80 and 100 millimetres is a pretty good measurement for that. |
| 04:48 | So I'm just going to make a quick measurement here now. |
| 04:51 | Doesn't have to be amazingly accurate. |
| 04:53 | I'm just using my calipers because they happen to be on the bench. |
| 04:56 | So if we get those reading around about our 80 millimetre mark there. |
| 05:02 | And just get the face of that heat shrink, 80 milimetres from the face of our connector there. |
| 05:10 | Excellent, so that's where we're going to recover that into place. |
| 05:14 | You also want to pay attention to the orientation of your labels as well. |
| 05:18 | Another nice way to make it look very finished and professional is to keep the text on your labels here in the same orientation in relation to the direction of your connector, keep that uniform throughout your harness. |
| 05:32 | What I like to do is have the test facing upwards when our connector is held so the connector tabs are also facing upwards. |
| 05:40 | So with that label in the correct position, I'm going to turn our heat gun on and get that recovered into place. |
| 05:52 | And then to finish that off we're simply going to slide our section of clear heat shrink into place. |
| 05:57 | Can pay to leave a few seconds in between shrinking down your label material and getting your clear heat shrink into place just to let any of that residual heat dissipate. |
| 06:07 | The last thing you want is for this clear heat shrink to start recovering while you're trying to slide it into place, as the Raychem stuff we're using here does actually have an adhesive on the inside as well. |
| 06:17 | So we'll get that slid into place. |
| 06:21 | Just so our label is nice and central in it there. |
| 06:25 | Should have around about a millimetre of overhang on either end, and we'll recover that down. |
| 06:43 | With that clear heat shrink recovered into place, that is this particular harness section finalised. |
| 06:49 | We've gone through the process of checking our pin out, we know that's all correct, it's now booted and sealed and labelled and looking really nice and tidy and professional. |
| 06:58 | What I'm going to do now is actually recover all the boots into place for the end of our harness section here, just to get our labelling materials sorted and out of the way and then we'll come back and we'll look at recovering this branch point boot into place, as the process is a little bit different and we're actually going to be using some epoxy sealing compound for that. |
| 07:19 | Because our boot here doesn't have any potting compound on the inside of it. |
| 08:23 | Working our way back down the harness I've got all our connector boots fully recovered and sealed into place on this end of the harness and in fact our mid section of the harness as well there. |
| 08:33 | I've got those just cable tied loosely out of the way as the point we're going to work on now is actually our transition point B. |
| 08:40 | We've got a 202K142 boot here and we're going to use that for sealing our transition point B, potting compound inside there, it's gonna really nicely strain relieve everything as it's going to go nice and rigid when it cools. |
| 08:53 | Now for this boot here you can get them supplied with a potting compound already applied to the inside. |
| 09:02 | When I'm using them for a transition point boot like this I actually like to get them supplied without that potting compound and put our own potting compound in which I do have prepared in a syringe here. |
| 09:14 | This is just the same Hellermann Tyton V9500 that we've used in other parts of the course. |
| 09:20 | Raychem S1125 or Resin Tech RT125 are also applicable for this application. |
| 09:26 | They are essentially interchangeable when you're building a harness so don't stress if you can't find the Hellermann V9500, either of those two products are going to work just as well. |
| 09:35 | The way that we're going to approach this is with our harness exit point first which has actually got our lipped section of the boot. |
| 09:43 | I'm going to put a bead of our sealing epoxy compound around here on our sections of abraded DR25. |
| 09:52 | I'm going to try and get a wee dollop in the middle as well there to seal in the centre of all those harness sections as they exit that point. |
| 10:01 | We are going to come back, once this has actually cooled, and using some more epoxy compound, we're essentially going to pot that join much like we have done for when we're making a soldered connection to a sensor that may not have a connector which is applicable for a motorsport application. |
| 10:18 | That is going to be essentially the same task but we will show it in detail as well. |
| 10:25 | Once we've got that end of our harness transition point here all shrunk down, we're going to work on the other end here, we're going to put another bead of our sealing epoxy compound down and we're going to continue shrinking our boot in this direction onto that bead and that's going to lock it into that DR25 and totally seal the harness from that end as well. |
| 10:46 | Another wee detail to be aware of when using these boots, either on a connector actually or as a transition point like this is if you get the 202K series like I've got here supplied with the wee eyelet on it, which takes a chain typically in a connector application to put a sealing cap for the connector on, you want to be aware of where that's going to end up. |
| 11:11 | In this instance I've got our harness set up between my two vices here, with how the harness will lay in the vehicle facing up. |
| 11:20 | So I'm going to keep that wee eyelet facing up as well and that's going to keep it in line with all of the other eyelets on the harness as well and just give it that little bit more uniformity when it's all recovered into place, keep it really nice looking. |
| 11:33 | When you're doing this, if you can get a vice set up or a fixturing setup that actually holds the harness vertical, it can be a little bit easier. |
| 11:41 | You can see I've had to go underneath that there. |
| 11:43 | Once we've got the boot in place it's not gonna matter too much 'cause if any drips off there it's going to drip onto our boot and then it's going to get recovered back into place and seal nicely but if you can hold it vertical, it is a little bit easier. |
| 11:55 | With everything checking out there, I'm going to put a glove on my left hand here. |
| 12:02 | When you're doing this, you might actually need to reposition the boot a little as you're recovering it into place and things are going to get reasonably hot in this area as we do need to put quite a lot of heat into these boots to really get them to recover nicely into place. |
| 12:15 | And if you're going to have to do that, absolutely wear some sort of PPE on the hands because they do get pretty hot and it's definitely possible to burn yourself. |
| 12:41 | We've got our branch exit point recovered into place there. |
| 12:44 | And that has recovered down nicely onto that bead of epoxy compound that we've put in there. |
| 12:49 | As I mentioned, we do have some gaps in between all our harness section as it's exiting this branch point at the moment. |
| 12:56 | We are going to go through the process of potting those with our epoxy. |
| 12:59 | However we're going to get the other side of this recovered into position first. |
| 13:03 | And that's actually going to seal off this join. |
| 13:06 | So if any of the epoxy that we put in from this side dribbles down, it's not going to end up down the other side of our harness. |
| 13:12 | This is exactly the same procedure. |
| 13:14 | I'm simply going to put a bead of epoxy compound around the harness section here and then I'm going to recover our boot down onto it. |
| 13:26 | Wee slip with the syringe there while I was putting that bead of compound into place so I've ended up with a wee dollop of our potting compound on the outside of our boot here which is not something we really want as it's not gonna look great when we recover that back into position. |
| 13:40 | If you do strike that same issue, before it's cured, it's pretty easy to remove with a bit of isopropyl alcohol and a rag so I'll just go and wipe that wee bit off there. |
| 13:53 | Being careful not to smear it anywhere else while we do it. |
| 13:57 | With that sorted, gonna turn my heat gun back on and we're gonna continue to recover this boot down in this direction and get it fully shrunk into place. |
| 14:19 | It's very important once we've got that boot recovered down that the harness is sitting in your fixture as you're going to want it to be sitting in the car as well. |
| 14:28 | With that boot shrunk down it's going to cool and it's actually going to become very rigid which is excellent because it'll be giving us that strain relief that we're looking for, but it is going to lock that point of the harness in that position. |
| 14:40 | It was also very important that when we were applying the heat to recover this boot into place, that we applied it as evenly as possible, working it around with our heat gun and watching how that boot shrunk and applying heat as needed where necessary. |
| 14:55 | The H end of the boot here or the lipped end that would typically be pointing towards the connector, if we were using this boot on the connector, tends to shrink quite evenly because it's a bit thicker, it's got larger thermal mass so it's less important that we apply that heat completely evenly to get a really nice even shrink on that. |
| 15:16 | So that has shrunk down quite nicely. |
| 15:19 | Once we get to the J end of the boot here where things are a bit thinner, an error in move with the heat gun can actually become quite disastrous. |
| 15:27 | So you want to make sure that you are applying that heat absolutely as evenly as possible. |
| 15:32 | And as you do so, you will see the boot fold up in places. |
| 15:35 | If that happens, simply move around to the other side of the boot and give it a little bit of attention there and that will recover that section of the boot and actually pull that fold out. |
| 15:44 | And just work in that way down the end of the boot here and get it recovered onto the harness nice and evenly. |
| 15:51 | That's going to be making a good connection to our bead of epoxy compound under there now. |
| 15:57 | It's going to have flattened it out, biting into both those materials and giving us that seal that we're looking for. |
| 16:02 | Now once that boot was recovered into place, I came back and I gave it a good overall even heat for at least 30 seconds, just to make sure that it was as completely recovered as it can be and it's going to be fitting the harness really nicely and gripping it really tightly. |
| 16:18 | So as this has cooled down enough now to touch, you can see it really is nice and rigid, gonna be giving us that good strain relief, and the next step of the process we're going to come in with our epoxy compound again, into our exit section of the harness here and it should just fill in all those voids and make sure that's fully sealed. |
| 16:37 | Got my syringe of epoxy compound here, so we're simply going to come in here and fill in those voids. |
| 16:43 | It's exactly the same procedure as we did do for the engine position sensors earlier on in that module in the course where we needed to pot those 'cause they didn't have a particularly appropriate connector for our motorsport application. |
| 17:14 | Once again any errant mishaps can be cleaned up with just a little bit of isopropyl alcohol on a rag, very easy to do before that epoxy compound sets. |
| 17:32 | Just a temporary cable tie in place there to keep everything organised while that epoxy is going to set up. |
| 17:38 | It is going to self level over the next hour or so before it actually gets stiff enough to stop moving so just keep an eye on it. |
| 17:44 | If you see any low spots appear in there, just come back with a little bit more epoxy compound and you can fill those in, it really will self level out quite nicely. |
| 17:53 | Once this transition point has set up enough to be able to handle, I'm going to come in and do exactly the same job on transition point A of the harness, get that locked and finalised and in position. |
| 18:03 | We're then going to move to our sensor and actuator interface connectors and we're going to shrink the right angled Raychem moulded shape boots onto those, we will show that process in detail. |
| 18:14 | Now that we've got both of those moulded shapes recovered into place, they're really giving our transition points here excellent strain relief and support. |
| 18:23 | You can see we've gone ahead and recovered the boot into place for our transition point A here, and we have potted both sides of that join as well and that's going to completely seal that and keep it protected from that motorsport environment. |
| 18:38 | Continuing to work down the harness now, we're going to recover the last two boot into place which are going to be at our interface connectors here for our chassis and our sensor interface which are on the bulkhead of the vehicle. |
| 18:49 | Now as you can see, this is where one of the key benefits of using our circular Autosport connectors comes into play in that the boots that go on those are large enough in their unrecovered form that we can easily get that into place over that connector body. |
| 19:04 | So we haven't had to stress about having that in place on our harness the entire time, knowing that we can come back and get that where it needs to be at any point. |
| 19:11 | Now when you're going to recover these boots into place, as we've said before with the ones on our transition points here, you are going to have to use quite a lot of heat and it is going to take a reasonable amount of time. |
| 19:22 | And for that reason your connector bodies are actually going to get quite hot as well. |
| 19:28 | So you need to put some thought into how you're going to hold those, in your vice. |
| 19:33 | In our situation here I'm quite lucky that our mount plate isn't actually in the vehicle yet so I can use that to attach my connectors to and have that mounted in our vice here. |
| 19:43 | This would be particularly important if you were using rubber or plastic soft jaws just to hold onto your connector body. |
| 19:49 | It can actually get hot enough that it will start to melt those. |
| 19:51 | A bit of a rag wrapped around there can help out a lot if you are striking that situation. |
| 19:58 | So I'll get our harness connected to our interface panel here. |
| 20:05 | Locked into place and that's gonna be the correct orientation for how this harness needs to head away down the vehicle. |
| 20:12 | We've got our connector boot in place, and we're simply going to recover that using our heat gun. |
| 20:18 | Before we do that, I need to get some of our sealing epoxy into place. |
| 20:21 | Now when you're recovering these boots, they are going to form a lip on the front edge and that lip is meant to interface with the lip on the connector here. |
| 20:30 | For that reason I actually like to put my bead of epoxy sealing compound on the knurling here as that's going to keep it back from that lip, it's going to avoid it possibly squeezing out the front end. |
| 20:40 | It's not the end of the world if that happens, you can clean it up with some isopropyl alcohol on a rag, but it can end up looking a little bit untidy if it doesn't actually squeeze out particularly evenly. |
| 20:49 | Putting it on the knurling back here usually avoids that problem. |
| 20:53 | We're going to approach this the same way as we did for our transition points. |
| 20:56 | I'm going to shrink down that J end or the lipped end first onto our connector and I'm going to have to be reasonably careful with this. |
| 21:03 | I've actually got the smallest end directing the heat on my heat gun here so I can really get in tight around this end and get this boot to start forming its right angle shape before it starts recovering down the H end here onto our harness section. |
| 21:20 | Now it is possible that we will get some heat flowing or some heat spilling onto that H end there and if it does start to recover down, we're going to have to pause the process and make sure that we get our bead of epoxy sealing compound into place on our abraded DR25 here because if the situation is that that is just going to recover, there's not a lot we're going to be able to do about that, we're just going to have to recover the boot in one operation. |
| 21:48 | And absolutely when you're doing this with these boots, you are going to have to wear some sort of heat protection because you're going to have to be handling this boot while you're actually recovering it, it's going to get pretty hot. |
| 21:57 | So a good heat protective glove or even just a general workshop glove actually does a pretty good job of that. |
| 22:04 | So I've got my epoxy compound mixed up here, got it in my syringe, and I'm just going to put a bead around on this now. |
| 22:21 | With our bead of epoxy there I can get my glove on and we can get our heat gun out and start recovering that boot into position. |
| 22:35 | What I'm doing when I'm recovering this boot is I'm trying to keep that heat nice and even but if anything I'm probably gonna focus a little bit on the inside here and try and get this boot to start forming its right angle and really recovering down nicely onto our connector here. |
| 22:51 | Keeping the heat away as much as I possibly can from our outlet end here. |
| 22:56 | Now it's reasonably obvious which direction these boots are actually going to form their right angle in as they recover. |
| 23:01 | If you're ever in any doubt though, these Raychem 222K boots which is the part number for their right angle boots, will have the wee eyelet for mounting a connector cap to on the inside of that join. |
| 23:16 | So if we keep that on the inside of our right angle bend there, we know we're going to recover it into the correct position. |
| 23:30 | So that J end of the boot there, the lipped end, has recovered down really nicely, that lip has interfaced onto that connector body and it's actually locked on there really well so we're not going to be able to remove that now but we can actually still rotate it just to fine tune and get that exit angle completely correct as this is going to sit in the car just before that epoxy compound actually sets up. |
| 23:54 | What I'm going to do now is get a bead of our epoxy compound on our abraded section of our DR25 here and just continue shrinking that boot down, making sure to support everything with my hand here, just keep everything in the correct orientation, that's gonna shrink down nicely and lock everything into place. |
| 24:24 | Little bit tricky to do that out of position there while we've got this in shot on the camera but I've got that bead around there now so I'm going to flick the heat gun back on and just continue recovering that down into place. |
| 24:55 | Got that boot recovered down into place, it recovered down really nicely, had a little bit of epoxy squeeze out at our outlet J end here. |
| 25:02 | You can just tidy that up with some isopropyl alcohol on a rag before it sets up. |
| 25:08 | You have got quite a bit of time to do that so don't stress too much if that happens, that isopropyl alcohol will remove the unset epoxy compound quite nicely and you can end up with a really nice filleted bead around that outlet. |
| 25:21 | Just gonna let that cool down and set into its final position now, then we're going to go through exactly the same process installing the last boot on this harness into place which is going to be on our actuator interface connector here. |
| 25:33 | That's a 16-26 connector body so it's going to be a 222K152 boot. |
| 25:38 | The procedure is identical to what we've just gone through here though. |
| 25:42 | I'll have it mounted in my vice, we'll recover that into place and that is actually going to complete the process of recovering all the boots into place on our harness and totally sealing it, and that's going to keep it protected from the environment when it's in use in the vehicle. |
