J53 fixing up Others Engineering

[Warwick Marflitt]

Well flipping a boat by yourself is a challenge. It's amazing what you can do with a Tractor,old post, a railway iron... load binders and thinking....

[Warwick Marflitt]

So now it's back in the barn. The second phase of repairs continues..... There's a few low spots from Core flute being a bit uneven... with a bit of chopped strand and epoxy in them with the 5 layers of double bias and chopped strand it'll be as good as I can get it..... Cheers guys...

[hamjet41]

Fascinating to follow your work Warwick. Awesome job

Cheers

[Warwick Marflitt]

Thanks Hamjet
So I pulled the nylon peel ply off this morning and put the wooden bent-edge over the new
bit of glass.... then the good ole string------line!!!
It's fixable and adds thickness and strength to the bit that touches first....So a little time and extra product will see it touching the string....

[Warwick Marflitt]

I did position the core flute backing to be lower than the finished surface to allow for the 5 layers that have to be applied to replace what I cut out. the original hull was around 10mm thick. In places it was worn away from previous scrapes and hadn't been replaced when repairs where attempted.... So the adventure continues......   

[Kagua84]

I refurbished the centre my J52 a few years ago. The layers of fibre glass were worn through. I had some previous experience with composites and discussed it with an industry expert which I had used for composite issues at work.

He suggested to use aramid (Kevlar) layers with the glass. The final layers had to be glass as the aramid weave and fibres will show through if the gel coat is breached. We also used an epoxy two part resin rather than a polyester resin.

He explained that the aramid works well in combination with other composites, aramid-glass and aramid-carbon can give different properties. The theory was that the layers of aramid would help with impact. I have three teenage sons, so I expected a few minor mishaps, biffs and scrapes that can occur with jetboating. So far we have done nothing that would test the theory as the main uses of the boat have been river and harbour.

I had to take the hull to a workshop as my suburban driveway was unsuitable for the repairs. The cost of the aramid was more than the glass mat, I still have some left in the garage, it's actually yellow in colour. I should have a few photos of the repair which was done a few years ago which I could dig up if you wanted to see them.

[Warwick Marflitt]

Thanks for that info Kagua84. I'm using West Systems 105 Epoxy Resin and alternated layers of chopped strand and double bias tape. I'll finish it with epoxy resin and silicon carbide to give it a bit of wear resistance..... To be fair.. the hull was built in September 1973 so it is 48 years old....
More pics. Had to make up a centering device to hold the copper bends for drilling 20mm pipe holes as I don't have a drill press it was the best way to get it sorted.   

[Warwick Marflitt]

 

[Swift12]

that copper stuff is sexy Warwick....bet ya can't wait to silphos those together....pics please....

[Paul]

Had to make up a centering device to hold the copper bends for drilling 20mm pipe holes

That actually pretty clever - kind of like line-boring.

Soo, that was a copper cutter, cutting copper?  How many times did you have to recreate/redo the 'cutter' teeth?

[Kakapo76]

Really enjoying this thread- nice to see some different skills on display- well done.

[Warwick Marflitt]

That actually pretty clever - kind of like line-boring.

Soo, that was a copper cutter, cutting copper?  How many times did you have to recreate/redo the 'cutter' teeth?

No I used it to get the wooden guide plugs, hole the size of the pipe OD. In the picture with the big red watch makers spanner. I'm turning the wood around the copper cutter to shave it out to size... The woods a bit of Jara? Hardwood off an old BBQ I was surprised at how well the soft coppers teeth cut it out....
Copper does work harden and the filing and twisting may have had some effect...

[Paul]

So what cut the holes in the copper elbows - the teeth on the copper or just used the carbide burr?

[Warwick Marflitt]

Back to the fiber glassing.... It's like baking a loaf of vegans certified bread .... lots of procedures and steps to follow to prepare for the main event.... Sanding, finding all and any faults(Air pockets voids or cracked old glass)and grinding them out. Cleaning the work area and not contaminating the area with oily hands, synthetic rags,or bird poop, dust etc....Then! pre cutting all the fabric to shape and in increasing size to get the build up and shape correct. Having enough resin to complete the job in one go....
The job will start with mixing up a brew of thinned epoxy and painting onto the areas to key it for some epoxy thickened with 406 Colloidal Silica and some finely chopped strands of glass fibers.... This will be mixed to a peanut butter consistency and used to fill and level the voids,cracks and low areas.... While these are getting sticky I'll drink lots of water to lubricate my brain so that I won't make any ...
I'll mix up some resin and start laying on the mat alternating with chopped strand and Double bias mat.
5 layers should see it close to the level line then I have the front portion of the bows keel to the main repair to blend into the whole job with a layer of chopped and then a double Bias some woven mat and finish it with a layer of peel ply..... So that's the plan thus far.... then it'll be the silicon carbide wear coat/coats and some paint or graphite epoxy mix as a top coat..... And I'll have to reset the trailer rollers when its all topside up again...       

[Warwick Marflitt]

So what cut the holes in the copper elbows - the teeth on the copper or just used the carbide burr?

A step drill files the carbide burr? and a sanding wheel.... The wood guide was really just for getting the correct alignment.... If I had a pipe notcher it may have been quicker and easier,,,, but soft copper and sharp hole saws grip and deform copper pipe before you can say SH!T.... So a bit of time and measuring got me there in the end and gives you lot something to look at