Epoxy Selection

[darrenyorston]

I know this may have been done to death however I am about to start to repair a number of things on our wooden boat "Jackpot". There are a few gaps between planks in the transom that I am intending to fill with epoxy. After a fair bit of research I am choosing to go with Bote Cote and have a supplier within 10 minutes of work.

Which of the Bote Cote products do I need? The gaps are maybe 2mm however they do allow some water in. Once filled I will be sanding and repainting. There are a number of other areas that I will be filling as well such as the tops of countersunk crews and other small gaps where screws have been removed and not replaced.

Secondly around the fresh water deck filler there is a slight bit of chipping to the wood. There are no rot issues here so I would like to seal it up before rot occurs.

[Boatmik]

Hi Darren,

What construction method is the boat.

If traditionally planked of real wood then epoxy may not be the right way to go. But if it is plywood or has been fibreglassed then the method below will work fine.

Resin and Hardener
Pumps to suit the size containers of the above (hint keep the resin warm)
DADDLES - what's the link to our discussion about light boxes?

That's the obvious bit.

Now as far as the filler powders.
High strength gluing filler - gives a structural bond but hard to sand
Lightweight filler powder - sands easily but not very strong.

You definitely need the high strength one for the gaps in the transom. If you work neatly the sanding won't be too bad - but if you have a lot of little bits to fill in a non structural way - then it might be worth getting the lightweight filler as well.

As far as filling the cracks goes. Mix up resin and hardener - mix well scraping the sides and bottoms of the container. Brush the unthickened mix well into the cracks. A good tool to do it with is a 1" disposable brush with the bristles cut down to a length of about 3/4".

Dip the brush into the epoxy one last time.

Then add the thickening powder to the container mix it in well - probably need a peanut butter consistency unless working horizontally (you can use a honey consistency if horizontal.

Use the epoxy on the brush to get one more coat into the cracks and then fill with the thickened resin.

Hope this helps

MIK

[Daddles]

Here's the link to the light box selection. You'll notice that only Mik and I took it seriously :cool:
http://www.woodworkforums.ubeaut.com.au/showthread.php?t=34266

Don't forget, if you want to colour the poxy the same as the timber, you can use fine sawdust ... just a pinch will do.

Sand the stuff while it's still green ie, within a day or two. You'll be amazed at the difference. Fresh paper is a good move too, and some suction on your sander makes the whole job less intolerable (don't be fooled into thinking that anything to do with boats is easy, especially when you combine epoxy and sandpaper :( )

The other thing is, although poxy isn't supposed to shrink as it sets, it flamin' well does. Like using ordinary putties, leave the fill slightly proud and then sand back. The beauty of poxy is there's no problem with gouging a bit out and having another go if you make a mess of it ;)

And a Bote Cote supplier 10 mins from work? Such luxury.

Richard

[darrenyorston]

Here's the link to the light box selection. You'll notice that only Mik and I took it seriously :cool:
http://www.woodworkforums.ubeaut.com.au/showthread.php?t=34266

Don't forget, if you want to colour the poxy the same as the timber, you can use fine sawdust ... just a pinch will do.

Sand the stuff while it's still green ie, within a day or two. You'll be amazed at the difference. Fresh paper is a good move too, and some suction on your sander makes the whole job less intolerable (don't be fooled into thinking that anything to do with boats is easy, especially when you combine epoxy and sandpaper :( )

The other thing is, although poxy isn't supposed to shrink as it sets, it flamin' well does. Like using ordinary putties, leave the fill slightly proud and then sand back. The beauty of poxy is there's no problem with gouging a bit out and having another go if you make a mess of it ;)

And a Bote Cote supplier 10 mins from work? Such luxury.

Richard

Thanks fellas! I will take a pic on Saturday when I am there and post to show what I want to do. The Bote Cote supplier is Trend Timbers near Windsor NSW. They have marine ply as well for sale. What's the difference between gabon plywood and pacific maple marine plywood?

[Boatmik]

Gaboon (Gabon, okoume) is lighter which is really nice - but it is more expensive

the quality has been really variable over recent years. Look for good faces and few voids along the edges of the ply - voids shouldn't be any wider than a mm or two and maybe one or two a sheet.

Michael

[meerkat]

Here's the link to the light box selection. You'll notice that only Mik and I took it seriously :cool:

How rude !! I took it seriously..... eventually:D

[Daddles]

How rude !! I took it seriously..... eventually:D

Someones got to maintain the standards of this forum ... ie, down in the bilge :eek:

Richard

[meerkat]

Gaboon (Gabon, okoume) is lighter which is really nice - but it is more expensive

the quality has been really variable over recent years. Look for good faces and few voids along the edges of the ply - voids shouldn't be any wider than a mm or two and maybe one or two a sheet.

Michael

If you are going to get the gaboon, (from experience) pick the sheets yourself.

Not sure how to find the voids, in one of the sheets I recently got I found a void that was up to 3 mm wide and a couple of cm long. Fortuneately for me where it was didn't impact the end result too much.

Andrew

[Boatmik]

If you are going to get the gaboon, (from experience) pick the sheets yourself.

Not sure how to find the voids, in one of the sheets I recently got I found a void that was up to 3 mm wide and a couple of cm long. Fortuneately for me where it was didn't impact the end result too much.

Andrew

Good advice if possible. If you can't choose - ask about the quality of ply and make a bit of a fuss (nicely please) asking about voids to the person on the phone.

Then be prepared to (also nicely) ring them back if there are problems - it is possible that they may not have known about them.

Generally if the edges look OK then the rest will be fine too.

If you find a big area of delamination or a big void that was concealed (not that common if the edges are OK) then the supplier won't have known about it either and will be more or less happy to replace the sheet.

MIK

[darrenyorston]

Is anyone familiar with the Epoxy Resin system produced by International (www.yachtpaint.com (http://www.yachtpaint.com))? How does it rate against Bote Cote? Seems a hell of a lot dearer.

Are there any issues with using a 2 pack paints over the top of epoxies like Bote Cote? Do I need to utilise an undercoat if the wood is epoxied?

[Boatmik]

Hi Danny,

In tests years ago now (so may not be true anymore) Bote Cote and WEST were much better able to resist fracture than anything else on the market.

System 3 was a little behind - then everything else was a long, long way back.

If you use one of those three you won't go far wrong.

Regarding undercoats. There is generally no adhesion requirement to use undercoats for 2 pots

(STRONGLY RECOMMEND USING THEM FOR SINGLE POTS - SOMETIMES IF ENAMEL IS APPLIED DIRECTLY OVER SANDED EPOXY IT JUST SITS THERE WITHOUT HARDENING UP MUCH - COATS OF UNDERCOAT PREVENT THIS PROBLEM)

But even with two pots there are very good reasons to use undercoats.

1/ Topcoats are generally quite transparent - so you would need lots more coats of expensive top coat to block the view of the timber grain and any filling/filleting/patching you have done. Much faster and simpler to use coats of undercoat to make the surface an even white (though you can tint the undercoat to get a head start if you want). Undercoat is a little bit cheaper.

2/ Undercoats give you a chance to do a lot of sanding to get rid of imperfections in the hull such as orbital sander scratch marks, the last 5% of epoxy texture/dimpling etc etc etc.

3/ Putting undercoat on a hull allows you to see a lot of gouge and scratch marks you would never see otherwise. Also shows up imperfections on edges if not rounded evenly.

Best Regards
Michael

[darrenyorston]

All,
Finally remembered to take a photograph of the cracks I want to fill. These are in starboard side of the transom. At the widest point maybe 2-3mm apart. From the inside you can see light. I was told just to fill them and repaint the transom. Sikaflesk was suggested however so was Epoxy. I would appreciate suggestions about how to go about doing it.

Darren

[onthebeachalone]

Finally remembered to take a photograph of the cracks I want to fill. These are in starboard side of the transom. At the widest point maybe 2-3mm apart. From the inside you can see light.Woudn't you want to know exactly what was going on underneath before deciding how to deal with it?

From the little experience I have had with Sikaflex it would be a mistake to use it to fill cracks like that. It seems to me that Sikaflex is more suited as a flexible sealant under deck fittings, laid decks etc.

More likely that you would -
a) Clean out the gaps and fill with epoxy, plus filler.
or
b) Widen the gaps with a small router and insert this wooden splines, plus epoxy, plus filler.

But I wouldn't be doing anything without a good understanding of how the gaps are forming.

[darrenyorston]

Woudn't you want to know exactly what was going on underneath before deciding how to deal with it?

From the little experience I have had with Sikaflex it would be a mistake to use it to fill cracks like that. It seems to me that Sikaflex is more suited as a flexible sealant under deck fittings, laid decks etc.

More likely that you would -
a) Clean out the gaps and fill with epoxy, plus filler.
or
b) Widen the gaps with a small router and insert this wooden splines, plus epoxy, plus filler.

But I wouldn't be doing anything without a good understanding of how the gaps are forming.

I have been told the cracks are normal movement between planks on a vessel 46 years old in area that's not surmerged. From the inside they are not cracks just gaps towards one end of the plank. The outside looks the way it does as the paint has pulled apart.

[onthebeachalone]

From the inside they are not cracks just gaps towards one end of the plank.Are there some framing timbers holding them together inside? What sort of fastenings are holding the planks together? What sort of fastenings are holding the transom planks to the side planks?

[Daddles]

My thinking would be that if the planks are supposed to be able to move, as they would in a non-glued hull, you'd fill these gaps with something flexible, like Sikafex. Using epoxy wouldn't work because the first time the planks moved, you'd break the joint.

We need more info - such as, what sort of construction is the hull?

Richard

[Daddles]

If you're after a bit of fun, ask Mik if using silicone is a good idea ;) :eek:

Richard

[onthebeachalone]

Isn't it also a question of why there is that much movement at the starboard end of the transom planks, and not the port end?

If you just seal one end with something flexible like Sikaflex, won't you eventually get movement at the other end also?

So, should you not clean out the seam completely, across its length, and re-seal all of it? Also making sure that here is a good clean bond between the Sikaflex and the timber.

What if the real problem is that the fastenings are loose?

[Daddles]

What if the real problem is that the fastenings are loose?

You whack in a 4" nail, liberally douse with petrol, and con your mother in law into taking up smoking in the boat :D

Yes, first find why you have the problem, then fix it. One must do things in the right order, though it's often less fun that way :rolleyes:

Richard

[onthebeachalone]

Yeah well! I never found Sikaflex much fun to handle anyway. :p

[Boatmik]

Did I hear the word SILICONE?

:(

MIK

[darrenyorston]

The vessel is a traditionally planked cruiser built from Spotted Gum. The horizontal planks are single pieces from bow to stern (40ft long). I can see no indication of glue or corking between the planks of any type. The planks are attached to vertical supports [until I learn the terminology there is going to be lots of this beginner terminology] (roughly 2x2) between 6-12 inches apart which run from deck to keel. The vertical supports then have bow to stern beams (roughly 4x2) on the inside that the I assume keep them inplace.The keel is a single spotted gum beam (roughly 10x10). There are other port to starboard beams both at deck height and in the bilge (10x4) in certain places that I can see that are also sputted gum. The cross beams, from port to starboard, at deck height are probably close to 6x2 or 6x3.

I think the hull is either double planked or strip planked. From the inside the planks are horizontal (bow to stern) and the same on the outside. Double planked? Copper nails attach the planks from the outside.

Other than the ply main deck and ply upper deck the entire vessel is spotted gum. Keep in mind this vessel weighs nearly 20ton. I'd expect the wood to flex.

I have attached a photo of the entire transom area and you can see each of the planking quite clearly through the paint.

I have spoken to a number of shipwrights, in addition to my own research, and they all indicate that the planks move (hence why two pack paints are not suitable). The vessel is in dire need of a paint job, I think it was done in 1996, and the the starboard side transom does not look much different to other parts of the boat, such as the coamings.

The surveyors have said that the gaps in the starboard side transom need to be filled and repainted to stop fresh water from entering. Not that I have asked but none of them have said that the transom needs to be pulled apart.

I understand that movement in planks can indicate underlying problems however there is not much more I can do than have professional boat builders look at it. Should I keep looking around until I find one that tells me it has to be rebuilt?

Now for a positive tact...I understand epoxy is probably not the best choice to fill the gaps as it does not flex with movement? That silicone can't be painted? What's the pros/cons with Sikaflex? Can it be painted? Does it flex with movement? What other alternatives are available?

[Salted Nuts]

Hi Darren, I am guessing you would have completed this job already but thought I could offer you information of the product used on our boat to fill exactly the same problems. The shipwrights that performed the work on ours used International Microsmooth http://www.yachtpaint.com/australia//product_guide/fillers/AU_microsmooth.asp?ComponentID=18821&SourcePageID=13336#1 for all plank joints above the waterline. As the planks above the waterline do not need to expand "as much" as those below, you can get away with using a more solid filler above the waterline. I have attached a pic of them applying this product. You may be able to contact Bote Cote and find out their equivelant product. Sikaflex could also be used in this application, but you won't have a nice smooth sanded finish to paint over. Kind Regards, Pete

[darrenyorston]

Hi Darren, I am guessing you would have completed this job already but thought I could offer you information of the product used on our boat to fill exactly the same problems. The shipwrights that performed the work on ours used International Microsmooth http://www.yachtpaint.com/australia//product_guide/fillers/AU_microsmooth.asp?ComponentID=18821&SourcePageID=13336#1 for all plank joints above the waterline. As the planks above the waterline do not need to expand "as much" as those below, you can get away with using a more solid filler above the waterline. I have attached a pic of them applying this product. You may be able to contact Bote Cote and find out their equivelant product. Sikaflex could also be used in this application, but you won't have a nice smooth sanded finish to paint over. Kind Regards, Pete Good on ya Pete! No I have not done the job yet. She has been up on the slip for the last two days being anti fouled and having a diesel servcice. Turned out to be a pain in the butt. The antifoul was done in a day however the diesel service took nearly two days and was done at the last minute. ie 3.30 to 6pm last night. The mechanics ran out of people after they took the job.

I peeled off some paint around a window/portal yesreday whilst I was waiting. We had seen a bit of water beneath the paint so I wanted to see the extent of it. The window is mush for about 4 inches up and down. The window had not been sealed preoprly or has since become broken. We expected as much. Our intent was just to cut out the ply and replace. No can do. The window is set in a wooden sheet about two inches thick and about twenty feet long.

I am intending to dry out the wood and have a look at the area before I make a D on what to do. Anyone had experience with drying rot out and refilling with epxoy?

What's the opinion of the CPES product (http://www.rotdoctor.com/products/cpes.html) sold by the Rot Doctor is the USA? It seems to be utilised for this purpose. I noticed the it's epoxies are carried by solvents. My understanding with solvent based epoxies is the solvent evaporates and leaves gaps in the wood.

[meerkat]

Hi Darren

you are right, if you need to thin the poxy then use TPRDA (BoteCote product) or something similar. It thins it out and doesn't leave the voids.

If you haven't already, see Boatmiks website http://www.storerboatplans.com/Faq/faqindex.html (http://www.storerboats.com/Faq/faqindex.html)

I look forward to the responses etc.

[darrenyorston]

Hi Darren

you are right, if you need to thin the poxy then use TPRDA (BoteCote product) or something similar. It thins it out and doesn't leave the voids.

If you haven't already, see Boatmiks website http://members.ozemail.com.au/~storerm/Faq/faqindex.html (http://members.ozemail.com.au/%7Estorerm/Faq/faqindex.html)

I look forward to the responses etc.


Yes I had seen Boatmik's website. Most informative. If I drilled holes and injected epoxy thinned with TRPDA into the holes will it will leach through the timber or will it harden in the drill hole? I am looking for something that will penetrate throughout the affected area.

[Boatmik]

The above link is now

http://www.storerboatplans.com/Faq/faqindex.html

[hairymick]

G'day Mick,

That is an amazing link. I haven't had time to read all of it yet but I only wish I had found it a couple of years ago. It is like the ultimate "How To" resource and should be recommended/compulsory:D reading for anybody contemplating working with epoxy - and much more.

Thank you for shareing your considerable knowledge and expertise!

Respectfully

Mick