Cleaning stained wood

[Lecrenb]

Not sure if this is the best place to ask for help with this, if there is a better one please let me know! 

I have been approached by personnel from the Royal Canadian Navy's stone frigate H.M.C.S. Nonsuch to remediate damage caused to their model of the Hudson Bay Company ketch of the same name.

There is water damage to the hull caused when the fire sprinklers went off some years ago. There is also damage to the rigging caused, presumably, from dusting or similar cleaning attempts. The model is otherwise in good condition, and yes, I have certainly recommended a glass case!

The model was scratch built by members of the Edmonton Ship Model Society many years ago, and is of excellent quality. Unfortunately this club appears to be inactive. My intent is not to fully restore the hull, as I believe doing so would cause further damage and detract from what is now part of its history.

You can see from the pictures the stains on the deck and port side of the hull. The starboard side of the hull was not affected by the spray from the sprinklers. At this time I think the stains might be surface mold. The hull appears to be clear coated that has aged over time.

 

I am seeking advice on ways to remediate the stains, at least lighten them and kill the mold, if that is what it is, or if not to actually remove it.

 

[allanyed]

You may get more responses on particular methods for the different parts from corroded guns to moldy deck  if the pictures were all right side up. 😀🤪🤪  I got dizzy looking at them.  When was the model built?  

 

With all the other issues, it is good to see the rigging seems to have held up regarding aging.    Matching this is something to watch for regarding material and color, making sure it is miniature rope, not thread from the local craft center.  Good luck.

 

Allan

[druxey]

Perhaps consulting a professional museum conservator would be the prudent first step.

[mtaylor]

I agree with Druxey.  If there's mould on the outside, there's probably a boat load (pun intened) on the inside and that's a real problem to get rid of.

[rudybob]

I have used RMR-141 RTU Disinfectant and Fungicide with good success to remove mold around the house. It kills mold fast and can be wiped off with a rag. I have used it in and out of doors. KLR makes a similar product which I find less efficacious but still works

Good Luck with your project

Edited June 19, 2022 by rudybob

[Dr PR]

I have a PhD in microbiology, specializing in fungal physiology, and I operated a medical mycology (pathogenic fungi) lab for a number of years.

 

The grey stains look like dry rot - the same fungi that cause fences to turn gray with time. The fungi that cause this are dark grey to black (dematiaceae), and the stain runs deep into the wood. You can't wipe it off.

 

Mark is right - there probably is more mold on the inside, but if the wood has been dry for a while it won't spread more. But be careful! There will be spores and some of the fungi are opportunistic pathogens and can cause infections if your immune system is weakened for any reason (illness, chemotherapy, etc.). Don't breathe the dust or spores! Wear a mask!

 

You might be able to lighten the stain with kitchen bleach  (sodium hypochlorite) or oxalic acid.  Paint a bit on to the wood with a small brush and see what happens. Wash it off with water. Try it on a hidden place first if you can find one. This will not restore the original wood color, but may make the stain lighter and less noticeable. In any case the bleach will kill the fungus. You may need to remove any paint/varnish/shellac on the wood in order to get to the fungus.

 

Come to think of it, that's what we were doing with holystoning our decks. We used a bleach (oxalic acid) to lighten the wood! So you will be following tradition! Could be some real nostalgia there.

 

I wouldn't bet on this accomplishing much, but it might work.

Edited June 19, 2022 by Dr PR

[mtdoramike]

A strong solution of vinegar works great in getting rid of mold. But upon looking over the pictures, the display base got the worst of it. The hull and deck look quite weathered and gives the ship character. When restoring a boat, I try to only fix things that are falling apart, have come loose or something that greatly detracts from the model. To me, it would be a crime to remove or re-do an aged model to looking prestine again, which erases the journey that model has taken and the history of it.

Edited June 19, 2022 by mtdoramike

[Roger Pellett]

I agree with Mike.  It’s best left alone.

[Lecrenb]

Thanks everyone for the great replies!

I have in fact reached out to the Manitoba Museum in Winnipeg, who are the custodians of the 1:1 scale replica of Nonsuch, and who I believe have the plans used to build her. (She was built by J. Hinks & Son, Appledore, UK, in 1970 and sailed up and down both coasts of North America and the Great Lakes to commemorate the 300th anniversary of the Hudson Bay Company).  I hope they can help with a rigging plan and general arrangement, if not close access to the replica, as well as seeking the advice of their conservators.

I have no desire to try working inside the hull or removing planking, that is way outside my wheelhouse and would definitely do harm to the model. My intent is to stabilise any further deterioration and conserve it, then get it under glass.

 

I am working on the provenance of the model, HMCS Nonsuch personnel have had it for many years and are looking through their records for information. Although the Edmonton Ship Model Society is inactive, and most of their members have passed on, I do hope to turn up at least the name of the builder.

 

Sorry about the pictures being a bit cattywumpus, I used my phone and did not do any enhancements.

Regards,

Bruce

 

[Jaager]

Thinking about what Phil wrote,  - I lost an elderly dog to blasto -  and the interior being infected and  a source of future problems, what with the concentration of fungal invasion being higher than ambient,  I was thinking a gas to kill it.   

A gas that was an active fungicide would also probably be bad for model components.

If dormant fungus or fungal spores are not anaerobes then a significant time in a 100%  N2 chamber might turn the fungal infection part into inert organic material.

What about the bloom on the guns?  Is it just dried rain?  Is it an outgrowth and attached?

If it is a fallen powder, a simple, but tedious, mechanical removal may be the way.

It is essentially maleficence for a museum not to case a ship model.

[mtdoramike]

A strong solution of vinegar works great in getting rid of mold. But upon looking over the pictures, the display base got the worst of it. The hull and deck look quite weathered and gives the ship character. When restoring a boat, I try to only fix things that are falling apart, have come loose or something that greatly detracts from the model. To me, it would be a crime to remove or re-do an aged model to looking prestine again, which eraces the journey that model has taken and the history of it.

 

If you are looking for a rigging plan for the model, I would recommend looking for a rigging plan for the HMS Bounty, because this model has a striking resemblance to the Bounty.  

[Dr PR]

Fungal spores are resistant to all ordinary treatments. They are inert - their metabolism is halted, waiting for the right conditions to "turn on" again. They can "wait" for decades. So the N2 treatment or other gasses or other mild treatments will have no effect. Only soaking with strong anti fungal agents (bleach is a good one) or high pressure steam will kill them, but neither of these treatments would be model friendly.

 

The wood will be filled with inert spores waiting for more moisture to germinate and continue to decompose the wood. So keeping the model dry is imperative. It should be stored in a sealed case with desiccant. The desiccant should be replaced periodically. A humidity indicator inside the case can be used to indicate when the desiccant should be changed. Some desiccants change color (white to blue) when they should be replaced.

 

If you are in good health I wouldn't worry much about the spores. The wood rotting fungi are not normal human pathogens. But they still can cause infections in people with an impaired immune system. More likely they will cause an allergic reaction.

[Lecrenb]

Thanks very much for the good advice. I too was thinking vinegar or bleach, but I am going to hold off until I hopefully hear back from the conservators at the Manitoba Museum. 

I will also reach out for advice to the Calgary Naval Museum which is closer and where my corvette model is displayed.

I have not examined the cannons close up, but at least one seems to be missing, so I will consult with the Navy as to whether or not they want replacements built.

I will also post elsewhere in hopes of finding survivors of the Association that built and presented the model.

Regards all!

Bruce

 

[allanyed]

This entire topic has been fascinating and extremely informative.   I truly hope I never have to go back to this string for using the information. 😀

Allan

[druxey]

I would be very cautious before using any chemical and then casing the model. The case must have ventilation anyway, but off-gassing of residual chemicals such as vinegar will not help things. Again, I urge you to seek professional advice, if Dr. Per hasn't already persuaded you!

[Dr PR]

druxey,

 

You make a very good point! And it complicates the problem.

 

If the wood gets wet again (or high humidity) the fungus will spread. So the model should be kept in a dry place such as an enclosed case. But the case should be ventilated to avoid build up of gasses/fumes that would damage the model. My suggestion of using a sealed case with desiccant won't work.

 

And if chlorine bleach (sodium hypochlorite)  is used to remove the stain, the wood will out gas chlorine for some time. Chlorine is very reactive so you don't want that accumulating in the case!

[Lecrenb]

Interesting advice, and thanks very much for it!

I have heard back from the Conservators, and their recommendation is to use a mini vacuum and brushes to carefully remove any dirt and debris from the model. After that they recommend using cotton swabs with spittle (enzymes in saliva break down dirt and do not harm wood) followed by clean swabs to dry it. That should remove any dry mold, and any work beyond that falls into the realm of restoration, not conservation. The Conservators do not recommend using any kind of solvent, cleaner, sealer, or other chemical compound on the model unless restoration is desired. 

They do recommend a glass case with dessicant. 

At this point I have sent these recommendations off to the Navy to see if we are on the same page, and to see if they want any restoration work done. Next will be putting some numbers against the work I am prepared to do, and see where they land!!

Regards,

Bruce