Bombard Aerotec Re-Glue (Transom & Floor)

[bomberman]

The Following is a description...hopefully with pictures of my re-glue of my Bombard Aerotec transom and floor.
It is difficult to know where to start with this so I guess a couple of thanks first, to Bob for being the very important second pair of hands to Ross at Ribstore.co.uk for the advice and materials and Office888 for advice on solvents for removal of old glue.
Before I go through what I did and the how I would just like to state that this is not intended to be a definitive guide on what to do and how to do it, but merely a method (or sequence of methods) that I used to do the job. My hope here is that others with experience and competence way beyond mine can add advice for all or elements of the task, to better prepare others who are considering having a go at it.
To set the scene on my level of experience with this sort of thing…..0!!! I had never glued a boat or any other PVC item that I can recall, that said I would consider myself to be a relatively practical person. So you may be asking, why I had a go…the answer is why not, in my opinion I had nothing to lose and everything to gain and how hard could it be……
So I purchased the Aerotec from a well established internet auction site, got it home and then didn’t do anything with it of the engine for about 18-20 months. Upon realising a holiday was fast approaching where I wanted to use it I decided that it may be a good idea to have a look at it and ensure it was ok. Long story short, had to resolve a couple of valves leaking and whilst sorting this realised that a couple of areas on the top of the transom to tube, seemed to be detaching. I received some advice that if I heat it up and it comes apart easily then the glue is shot, if it requires a bit of force then it may be ok for a couple of years with small repair to the areas that had lifted. Hot air gun for a few seconds and it came off very easily, so the option of an easy fix faded and the time implications for resolving this became a little more concerning.

[bomberman]

I spent a lot of time reading around the job, especially on Ribnet, there are a few videos that show elements of it on utube and in terms of duration to undertake the consensus was about 20- 25 hours for an amateur. I would estimate I spent more time on it than that, but the key thing to bear in mind is that with this job, you spend a lot of time waiting…..that is waiting in between applying layers of glue, waiting for glued joints to go off and more importantly waiting for the appropriate weather conditions with the key element being that the humidity levels need to be less than 60%.
What did I use to do the job:
Humidity meter
2 litres of 2 part PVC Glue
1 litre of MEK
~2.5 Litres Methylene Chloride
Approx. 20-30 1” paint brushes (cut down length to stiffen up brush)
Mixing sticks
10ml syringes
Mixing pots (I got some for mixing paint made measuring out quantities of glue easier)
Couple of tubes of 1 part hypalon glue
Disposable gloves
Mask to eliminate inhalation of vapours (very potent)
Goggles
Scrapers…I used plastic and metal ones
Kitchen roll to wipe residue off the scrapers
Masking tape (used a couple of rolls)
Marker pen and paint pen
Hot air gun
Ratchet straps
Solid roller (to eliminate air in glued items)

First job – inflate boat to ensure it holds air, if it doesn’t sort that first.
For the entire job I left the tubes inflated.
I marked everything up so I had some indicator of position for when I was putting it back together again (used the white paint pen on the black pvc and black marker on the red pvc). Then next job was the removal of the drain bungs, which tapped out from inside the boat (used large diameter wood and was careful not to hit it too hard), following that I removed the bottom attachments for the zodiac wheels, which were affixed with some domed head flat bade screw head. One of these was bent and so took a while to remove and when I replaced I just used a hex head bolt of appropriate length (it doesn’t catch on the floor when inflated).

[bomberman]

Then started to piece by piece remove the sections of PVC that hold the transom to the tube, each step marked position and tried to take images also identified where the piece came from (I don’t have a great memory!)

[bomberman]

Once all the components of the transom where removed then I removed the floor, which in hindsight probably didn’t need meddling with as it was really difficult to get off, except a small area at the bow of the boat. One thing covered by the floor which I wasn’t expecting was what looked like a tear on the underside of the boat on each tube. There was marks around them that were possibly from when the boat was first made and given they were consistent in length and respective position, I can only assume that these are areas that maybe equipment was inserted to weld the tubes perhaps….but any thoughts gratefully received.

[bomberman]

As can be seen I used some trestles to raise the boat up as it was significantly easier to work on at waist height. (white markings on red tubes were present when I removed the floor/transom elements).

[bomberman]

So the Boat was completely stripped and it was at this point that I then started considering how I would be able to get it all back together, in the right place as the floor to transom was quite tight and then, the practicalities of re-attaching the floor being quite long.
So the next part of this was cleaning off the old glue after raising the question on the forum Office888 (many thanks) offered the suggestion of the Methylene Chloride. Although not entirely convinced on my technique and I think Office888’s subsequent postings I probably could have improved what I did as I didn’t clean it off after, but basically brushed it onto the area I was cleaning and then used a scraper the remove the old glue, which seemed to come off easily following a couple of applications. To assess when I had got it off I was looking at the surface and examining for consistency and no obvious glue remaining
Although be warned about using a metal scraper, especially on the floor where it is difficult to keep it flat, it is easy to stab/slice into the material, therefore especially for the floor, plastic scrapers were better and the flex in them made it easier.

[bomberman]

The transom was a different kettle of fish and after plenty meddling, the best way I found for removing the glue was a 3 stag process, first of all to run over the area with a sander, which contaminated the glue (maybe even softened it) with debris/dust from the sanding process, then I use the metal scraper to scrap it off as with the contamination in it, it came off a lot easier. This was then followed by another sand with a fresh pad to bring up fresh wood.
To clean the black veneer up I used an old knife and scraped it, it came off relatively easily from this surface.

[bomberman]

So this is maybe one bit that I got wrong, there were some materials used in the transom area that I thought were rubber and therefore prepared as rubber. The reason I assumed this was I had received some advice that if I burn a bit, melting up would indicate PVC and black smoke would indicate rubber…..it seemed like black smoke to me to treated as rubber…..welcome to comment if I have got this wrong so that anyone else doesn’t!!!! Therefore the black material that sits on the tubes in front and behind the transom, for the full length of the transom and the white bits that sit between the transom and the tubes at the top and bottom

[bomberman]

So now I have everything prepared and ready to reattach, the way I started this was by temporarily taping the white ‘rubber’ bits on to the tubes putting the transom in place and adjusting these pieces until they were in the right place. Then marked up where they went, painted on the hypalon glue onto the bits and then subsequently taped off the area on the tubes and applied the 2 part PVC glue (25:1 ratio and applied in 2 coats, after 1st one waited 25 minutes and then a few minutes after second coating, bringing into contact – same for all joints with the 2 part adhesive).

Once these bits where in place then we started to attach the white strips to the transom sides (which glue onto the tubes) therefore with these again, Hypalon glue to the wood, then the pvc glue onto the hypalon glue and onto the white pvc pieces. Also after bringing any of these together with the 2 part pvc glue, I ran over them with a roller to remove/reduce any air bubbles in the joint.

[bomberman]

Then gluing on the section that attaches to the inside (boat internal space side) of the transom and eventually will be reattached to the floor, I found to make this a little easier to position, the use of dowels in the holes for the zodiac wheels and the drain valves, helped with positioning and also working from one side to another and ensuring that no area that you were ready to press down to glue was close to the other surface as with the contact glue that was a nightmare to try and lift off.
Then this same piece was glued to the underside of the transom (considered doing this and the previous step in one, but think I made the right choice as would have been trying to do too much in one step…..and just didn’t have enough hands).

[bomberman]

Then once this part was attached the transom was ready to go back onto the tubes…a key part of the repair and therefore a nervous few hours. Ultimately trial fit, ensure you get your masking tape in the right place (allowing for a little spread…think they say 1mm) then when ready follow the gluing procedure, spread the tubes so that when you are putting it in place with the glue all on and ready both sides, you are able to work on one side at a time to ensure you get it in the right place and then, when you have them all in and lined up, push them together to get that initial adhesion and then get some ratchets and apply some pressure across the transom to clamp it up. Before I did this (and hoping you read this before you did it!!) I let a little air out of the tubes (not much) to ensure it took the shape of the transom and then a few hours later I pumped them back up to pressure and re-adjusted the ratchet straps

[bomberman]

Then the rest of the parts that attach the transom to the tubes could be put back on.

[bomberman]

Following this we were ready to put the floor back on and so once again preparing the transom and then subsequently gluing the floor onto the rear of the transom and the PVC part attached to the inside of the transom. Again using the dowels to locate the floor in the right place on the back of the transom.

Masking up the tube and applying glue, this was one part of the rebuild that if I was to do it again I would have done in a number of more steps as to glue the floor on, we did it in 3 or 4 stages and in hindsight would have done it in double that at least, but glued equal lengths at each side at a time. The difficulty here is where to the put the floor so that you can apply the glue to it and it wasn’t going to stick to itself

[bomberman]

Once I had the first part of the floor glued then I could attach the last pieces on the bottom that go over the floor and onto the tubes, therefore masked and glued as per previously described procedure.

Got the front of the floor attached and as can be seen it isn’t exactly where it was when removed, but it looks worse than what it was (that’s my excuse anyway!) but it was central which for me was the main thing. I could then put on the final patches onto the top of the transom.

[bomberman]

Last job was marine Sikaflex on the back centre of the transom (thanks Max)And there she is all pumped up and following a little abuse on the high seas, where there were no problems with the joints so hoping that it lasts for a good few years to come.
In summary, a long hard slog and due to tight deadlines I couldn’t do it how I would have liked, but ultimately got it done a few days before I went away and luckily the 2 weeks wasn’t spoilt by the boat not holding together!!! (first few hours didn’t go too far from the shore just in case!!)
So hope this helps some others who are maybe thinking of undertaking the job and like previously mentioned anyone who spots something I have done wrong, something I could have done better or different, please feel free to speak up so others have as much info as possible.
....if you got to the end of this novel, hope I didn't bore you too much!!!

[Fenlander]

As someone who has undertaken small repairs on an Aerotec I'm very impressed. As a matter of interest what age is the boat?

[bomberman]

Hi Fenlander, it's a 2001. I reckon the floor had a few years left it it with a small repair to the front and to be honest that would have saved a headache but at least now I have a bit of confidence in floor and transom.

[Fenlander]

One thing that seems to have been in your favour was that I assume it hadn't been messed with much before. Cleaning the OE Zodiac glue from mine was quite easy... the glue and mastic from previous owner's DIY repairs was more of a problem.

[bomberman]

Hi Fenlander, no I think you are right there, it didn't seem too tough, but it did take afair amount of time for all the bits and with little experience to compare against for identifying when I had got all the glue off probably spent longer than I needed to. But also think the solvent I used following the advice from Office888 will have made a massive difference with that part.

[jeffstevens763@g]

great thread also very impressed