DIY: Transom Repair Haines 1950R

[svranjic]

Gday John

I was going to suggest he contact you about this. I agree with what you and jarrah jack have said. If there is thick glass on the sides and only a thin sheet of plywood then just focus on the middle section.

This will be an easy transom rebuild..... just cut the skin drop the new ply, epoxy old skin and then glass the bevel. He should be able to get all that wood out without damaging the inner skin as its rotted pretty bad. I think the inner skin of those haines are fairly thick so he should be able to peel all the rotted wood away.

Apologies if Im a little behind on what is going on, Im still trying to finish the fitout on my rig lol

[odes20]

Gday John

I was going to suggest he contact you about this. I agree with what you and jarrah jack have said. If there is thick glass on the sides and only a thin sheet of plywood then just focus on the middle section.

This will be an easy transom rebuild..... just cut the skin drop the new ply, epoxy old skin and then glass the bevel. He should be able to get all that wood out without damaging the inner skin as its rotted pretty bad. I think the inner skin of those haines are fairly thick so he should be able to peel all the rotted wood away.

Apologies if Im a little behind on what is going on, Im still trying to finish the fitout on my rig lol

You must nearly be on the water?
JOhn

[mustang5]

Ok guys, been a good morning with good news so far. The transom ply is not connected to the outer wing wall ply so thats a positive. I would say that outer wall ply was just there for casting reasons maybe..

Ok so the old rot is coming off quite easy but I am about to go by a nice sharp chisel for the finer bits.

The inner skin is VERY thin, so I will have to do a bit of work on that but its not getting "too" damaged getting the ply off.

Heres some progress pics. Hope to have all the old ply out by today.. Hopefully.

Also, I measured the thickness, and I am going for 2 3/4 inch sheets of structural ply. Off to bunnings

[mustang5]

Oh, what is a good cleaning agent, or something that gets rid of all the rotted pieces of ply that are just sitting on the surface???

Like a degreaser for ply?? (Sorry Im a mechanic by trade, and a structural engineer.. I dont know anything about wood lol

[Jarrah Jack]

A disc sander would clean her up nicely even one of those small ones on the end of an electric drill.

I was thinking that perhaps the timber in the side panels was put there for ease of attaching things with screws. Screws never hold in glass and you need through bolts but timber holds the screws well.

[odes20]

Nice Work ! Well it was stuffed wasnt it! One wonders how many other boat owners are shuddering looking at this. Sad reality is that most boats around the 15- 20 yr mark can have these issues.

And no respect of brand names either!

Ive done Yalta Seafarer, Pride Haines and mates Nova as well. its amazing how many boats you open up could have been finished with more attention to datail, but were not and the issues that follow. Any boat bogged and capped at the transom can and will have these issues, and so many were done this way

Cheers
John
Mustang its such a good start mate and you will do OK now becuse youve bit the bullet and its just step bt step foward now
Cheers
John

[svranjic]

This is entirely up to you, but if you like you could cut the inner skin and take the whole lot out. Then re-glass the inside. This is one option open to you because the inner skin is so thin.

I had this issue on mine, it was taking forever to chisel the ply out as I could not separate the remaining plywood from the inner skin because the skin was so thin. It saved time to cut the inner skin and then re-glass the inside. When I re glassed I made it much much thicker.

Its up to you though. If you think you can remove the ply easily enough without damaging the skin then do that because it will save time. But be realistic about it.....

Remove all plywood, dont leave wood in there. This is the most time consuming part, everything after this is easy.

Your going well.

When you get your plywood, make sure its a bit smaller than the gap. I used a thin piece of mdf to make a pattern of what the new plywood piece needed to look like. Then I cut two sheets the same shape.

This was not shown in my thread but i then coated both sheets in epoxy resin. Then I mixed up some thickened epoxy and used it to glue both sheets together. I used lots of screws to hold it together until dry. Then removed the screws and epoxied the holes.

[mustang5]

Thanks Gents. Well I chipped away with the drill and grinder and its looking nice and clean now All the wood has come out pretty well and the inner skin in tact. However, it is very thin so I will be bulstering it up quite a bit. The reason behind this is that I have gone the external method on the basis a lot of the strenth of the transom comes from the bond from the inner skin & splashwell?? Am i on the right line here??

I measured up and given its a 20 inch transom, I got away with only requiring one sheet of 3/4 structural ply for $70 from bunnings. I went through the stack and picked the best one, without knots. And got them to cut it in half for me

Thank you John for your phone calls and messages so far, it has been very handy and helpful!

Ok so its now time to start thinking about the toughest part... Resin and glassing.

Ok so I have a parts list so far, thanks to John
- 8 litres of epiglass ht 9000
- 2 litres of hardener (1:4 parts). Are there any applications where I would require extra hardener??
- How much 450 chopped strand??
- How much 450 matting??

Whitworths Marine are right around the corner, epoxy resin is $90 per 4l. Thats not tooo bad. I have only spent $70 so far. So the missus is still very happy!! I even showed her how I added mulch in the garden!!

No pics as the phone was flat yesterday afternoon. Will take a few snaps tonight.

So the next steps...

If someone could clarify comment on the following, please let me know if Im on the right path:

- Cutout ply to shape, making sure it fits flush
- Epoxy inner sheet of ply, and insert. Put screws through inner skin to clamp and bond. ALSO, use chopped strand and resin on the outer edges of the ply to bond with perimeter?
- Epoxy outer sheet, place in transom and screw it to the inner sheet for the clamp. Connect the two with epoxy and 450 chopped strand.
- Epoxy outer fibreglass skin to the new ply.
- Grind a tapered groove, with the invert level of roughly 10-15mm depth, along the existing cut line. How far do I go to the outer edge with this taper??
- Fibreglass the join starting with thin small strips of matting, gradually increasing, and carry that on over the inner skin in the splashwell. Do I take this fibreglassing just to the edge?? Or carry it around the edges a certain distance??
- Remove highs, smooth sand, and repaint.
- Hope for the best


Cheers again.

[svranjic]

Yeh the epiglass resin is really cheap. I used west system and it cost me a fortune.......

If you are going to make the inner skin thicker you will need to grind all of the flowcoat / paint from the inside of the inner skin and around to the edges to allow a good bonding surface. I dunno how you will go doing this with such a thin inner skin.

Also you dont have to add glass between the two sheets of plywood when laminating to make your transom. West system describe this method in their boat building book. One of the reasons epoxy is used is due to the fact it can save you time because the resin itself is so much stronger than polyester. If you were doing it with polyester you would need fiberglass mat in between the two sheets due to the fact polyester resin without fiberglass mat is weak.

This also rings true regarding putting glass around the edges of the timber. When you mix thickened epoxy and see it after it has dried you will know exactly what I mean.

Thats not to say you shouldnt use glass mat in these situations, it is just a step that is optional.

One thing you should most definitely consider:

Be careful buying fiberglass mat for epoxy. You need powder bonded mat. The other type of mat is only suitable for polyster resins NOT epoxy.

Also fiberglass mat soaks up lots more resin than woven fiberglass does. Woven fiberglass is also much stronger. If I had my time again I would have used both mat and woven fiberglass. I used woven on the inside because it saved me a hell of a lot of epoxy and money.

The mat provides strength, not as much as woven, but is primarily there to build thickness. In west systems boat building book they actually use woven glass and dont even fill the gap till its flush, they lay a few layers of woven glass and then fill the remaining void. Im not suggesting you do this but it just acts as an example as to the strength benefits.

Also woven glass is virtually the same price.

Its up to you weather you go for both.

What looked like a difficult transom rebuild has actually turned out to be quite straight forward. Keep picking Johns brain he loves rebuilding transoms

[odes20]

I am at present guiding a friend at cairns thru this task but to my great pleasure i have not touched it! Igree it should be straight foward from here mr Mustang.

Cheers
John

[mustang5]

Yes its looking nice and easy from here on in!! Thanks to all your help!

Will keep you all posted at the next stage

[Jarrah Jack]

Hows the transom coming along Mustang ?

[mustang5]

Hey guys, sorry I havent had much to update, but good news!! All is complete

Posted a guide at http://bit.ly/fcdsg4 but will make a new post on Ausfish!!

Thanks all for the help

[frankgrimes]

Hey guys, sorry I havent had much to update, but good news!! All is complete

posted a guide at ###### but will make a new post on Ausfish!!

Thanks all for the help

Add some "_" in the domain name....your link was filtered.

Mick

[mustang5]

Yeah not sure why.. I thought the link was too long so I shortened it. See edited post