Thread: Another Wood Rot question....

Hiya, I gave your problem much thought and reckon this may steer you right. There's just a few more things to know first..

How large and how soft are the "furry" patches - diameter and depth of soft timber? For example, in a 9mm ply there are usually 5 laminations - any idea how many laminations are affected?

Is the timber oozing liquid when you put thumb pressure on it and therefore saturated?

Dry rot will not occur below the water line usually, however mold will. Is it mold, or rot?

There is an enormous difference between "as dry as possible" and dry. Dry ply will absorb almost anything that replaces the moisture - epoxy, polyester or eurathanes. However each of these reacts differently in the presence of moisture - poly may not cure, epoxy will cure but not fully bond and eurathanes will dry and bond but only randomly as they displace the moisture into pools within the timber. Dry is dry, not nearly dry. Sometimes this means drilling the area for increased ventilation over a long time before repairing.

Is the glass sheathing delaminated from the ply on the hull anywhere near the wet timber - coming unglued? This is worth very careful inspection as you can do all the interior work and have it undone in an instant if this is the case.

Finally, what is your budget? Epoxy is very effective in resolving patches under 8 inches diameter. Over this you would be wise to have a boat builder look at it, with fibreglass and poly resin in mind because it is about half the cost and you can cover twice the area for future peace of mind.

delamaree

Actually a bit more information about the boat might help.... type, size etc, even pics perhaps....

Originally Posted by shanan

I purchased a 28ft Alan Wright 1978 owner built sloop (backyard job) - it's diagonally lined ply with GRP/Fiberglass Sheath.

Hey bald sexy cute BLIND guy he gave the info
Prob a trip to the eyeologist and get the wood shavings removed
Pete

Oi, don't pick on Christopha, he promised to give Violet to me

Richard

It sounds like this surveyor is a bit of a risk.

Report him, he'll never survey another boat again, that should learn him!!

Sorry about the delayed reponse! I have been offline.

As for all the questions.....

QUESTION 1. How large and how soft are the "furry" patches - diameter and depth of soft timber? For example, in a 9mm ply there are usually 5 laminations - any idea how many laminations are affected?

ANSWER: Surface area of the furry patches vary. Some are small - under 10cm x 10cm - then others are larger - up to 20cm (approx. could be more).

You can scrape a finger nail along a section of ply and it will be hard, then suddenly soft - then hard again. Water does not appear to have penetrated the entire length of certain sections - just patches.

At this point the furry wood seems to go down between 1-2 laminations. I have only started rubbing at a couple of sections though and even on these - I have yet to apply a wire brush. At a "guess" I would say the deepest I have rubbed away would be 3 to 4mm and in tehse cases, I'm pretty sure I have hit solid wood. I will try to confirm that for you.

I do not know how thick the hull ply is! How do I work this out?

QUESTION 2. Is the timber oozing liquid when you put thumb pressure on it and therefore saturated?

ANSWER: Kinda hard to answer. How much fluid you looking for? They do not appear to be "oozing" too much. Some of the really damp sections released a little water when pressed, however the timber for the most part still seems quite firm - it's not like a soft sponge or anything. I can only press so hard when there is little give. If I ran the back of a thumbnail firmly over certain sections I might have been able to force liquid out. Could not do that now though - bit dry for that.

QUESTION 3. Is the glass sheathing delaminated from the ply on the hull anywhere near the wet timber - coming unglued? This is worth very careful inspection as you can do all the interior work and have it undone in an instant if this is the case.

ANSWER: Unfortunately the antifoul covers many of the sections in question as they are all towards the bottom of the hull (I'm working on that antifoul though...).

To my untrained eye - where sections of the glass are viewable over the damp wood - it still seems to be well attached to the boat.

The skin is VERY thin on this boat though. When looking at the skin - very tiny voids CAN be seen, however these mostly appear where the heads of timber screws and nails have been (eg regularly spaced voids where nails heads should be). Other small randomly spaced bubbles are viewable (3-4mm) - HOWEVER these can appear on completely dry sections as well. They are not necessarily located near the damp areas.

To explain further..
The ply has been diagonally lined on the hull and the diagonal joins of these lines can also be seen through the glass. Again - sometimes these lines show tiny voids. These voids can be 1-2mm wide, but do not really travel along the entire length of the diagonal join. I should say that I can see NO severe delamination anywhere on the boat. I can only see tiny bubbles/voids which appear on different sections on the boat - again - some are not even near wet areas.

This being the case - I figure a lot of these TINY bubbles have been as they are for a looong time.

I will try to take pictures of these.

QUESTION 4: Finally, what is your budget? Epoxy is very effective in resolving patches under 8 inches diameter. Over this you would be wise to have a boat builder look at it, with fibreglass and poly resin in mind because it is about half the cost and you can cover twice the area for future peace of mind.

ANSWER: I paid 13K for the boat and it cost me another 3K to get it to melbourne. Add to that dock fees - it's getting up there (considering all the work that needs doing). I do not want to spend more than it's worth, but I do have some money set aside to spend on the boat and would like to see it done properly.

Put it this way - I will pay what I need to to get it done properly. However I will endeavour to use my own labour where possible.

As for a boat builder - if anyone can recommend someone in melbourne who knows timber and fibreglass and does not mind going to the boat to work on it (currently in dry dock and westernport marina/hastings) then let me know!!!
Don't mind paying cash either!

Picture of the boat attached.
Picture 100-1856 is one of the damp sections. Kinda hard to see though.
Will try to take more helpful pictures - these were taken by surveyor.

Shanan,

Being a ply boat owner and boat builder, I can offer some advice that will save you time and money.

Firstly, you are probably a bit dark about the surveyor in Brisbane. Were you present at the survey? If not, and you haven't got that much experience in ply/timber boats you may be over estimating the problem. I would go to the small ships surveyors association www.smallships.asn.au and find a local surveyor who is familiar with timber construction. Get them to meet you at the boat and run through the original survey and your concerns re- rot. They can provide advice on how the repair should be carried out and you can get them back occasionally to drop in and check the work to see if you're on the right track. Most likely they will have other work in the same area so it shouldn't cost much ( probably around $50.00 an hour). At least this gives you an independent view as if you go directly to a shipwright, they may ( and I say may) over prescribe repairs. With a surveyors advice, you are sort of forewarned. Additionally, the surveyor can recommend timber boat repairers in the area that he knows do good work.

If there is rot, don't believe that you can just fill it up with some type of penetrating epoxy - the rotten area needs to be ground out ( a disc sander is good for this) and either a replacement piece of ply put in ( bonded with epoxy) or you could use fibrelass and epoxy resin to rebuild the original laminate strength. Do not, under any circumstances use polyester resin for repairs or bonding fibreglass to wooden boats.

From the pics, she looks nice.

regards,

Andrew

She's a lovely boat. When she's all fixed and you're wandering around the southern coasts looking for someone to show off to, pull into Adelaide so I can have a good drool.

Richard

Looking at the pictures, I would guess that your boat has been cold molded. 2 or 3 layers of vaneer layed in opposing directions and glued with epoxy. Check www.woodenboat.com - I seem to remember them having a book on how to repair cold molded hulls


cheers
Warren

Originally Posted by WRB

Looking at the pictures, I would guess that your boat has been cold molded. 2 or 3 layers of vaneer layed in opposing directions and glued with epoxy. Check www.woodenboat.com - I seem to remember them having a book on how to repair cold molded hulls


cheers
Warren

WEST System have an excellent cheap booklet of wooden boat repair and restoration. About $ 10. Huge amount of info - good illustrations.

http://www.atlcomposites.com/