Dry out moisture?

I have dried wet wood with halogen lamps. It is very dangerous. There is a critical minute where the moisture finally leaves and there is nothing but dry wood. It still takes a long time and in your case; it might boil paint, crack gelcoat, etc. The hard part is it can take hours to dry and seconds to burn; so you cannot leave it. I walked away from a boat transom that I was drying out and fortunately I smelled it start to burn and ran to it. I should never have left it out of my reach. I would advise you avoid the temptation to use lamps or heed my cautions. My job required a repaint; so was less important when the gelcoat cracked from heat, but I was minutes away from a fire.

 

Moisture meters only tell the water content near the surface. I would do a screwdriver poke test to determine if fully waterlogged or just the surface affected. The surface moisture will dry quickly once affected fibers are exposed to ventilation. Truely waterlogged wood takes a very very very long time to dry. Logs are dries slowly for years before being sliced, and then the slices allowed additional time before final sizing. If poker penetrates more than a 1/8 inch consider replacing rather than drying.

Forsed air ventilation requires an exit as well as input holes. Rapid drying increases likelihood of worping or splitting.

 

Thanks for all suggestions!

The boat has been stripped of paint. So cosmetic issues is no concern.

When I touch the wood (sanded off some resin) it feels humid. When pushing in sharp objects it's softer than the above wood beam which shows 10%.

The wood beam with the high readings is one of two pieces off wood glued/glassed together. The one on top is the bad one. The one under is Reading 15%.

We are located in the tropics. Dry season. 45% humidity.

I understand a better meter would be a good shot, but I guess My wood still is having high numbers of moisture.

But anyway, I have not opened up the whole beam yet, which might be next move to see how rest Of the beam is. Would a hair dryer do any help?

One idea I got was to put in another wood beam in the box. And leave the humid one in place.

 

Would a hair dryer do any help?

IMO hairdryers make very fine wood dryers. Not very hot and lots of moving air. All dryers will only work surface fibers. It takes time for the water to wick away from the core. Slow and steady wins this race.

One idea I got was to put in another wood beam in the box. And leave the humid one in place.

Bad idea! New beam unlucky to be sufficiently attached to the hull, float or wet beam. Moisture and rot originisams will migrate from wet to new beam.

Moisture must be removed. Either slowly by drying, or quickly by replacing beam.

 

No and no.

The hairdryer will be endless days of handholding; not to mention dangerous w/o gfi near water. This job will take weeks to dry.

Adding another beam = 2 wet beams.

Send us a picture or two; it is difficult without perspective.

Blueknarr’s point about an exit for damp air was passe’. It is a must if you didn’t gather.

If the beam is exposed to the elements; you’ll need to tent it and still run heat and air by it. If you are in the dry season; get on it now. It’ll take about a month to dry out.

 

Blueknarr wrote his post as I wrote mine; they are independent. His posted like 5 seconds before I hit post. Just so you know.

 

If you could get maybe two hair dryers running; it may do the trick; start on low heat and fast air and change to high heat after a couple weeks.

...but you have to mount them

 

Fallguy and I must be in time sinck

One thought I had just after I hit post.

Could powered desicants be packed in and around beam. Would be expensive, but could speed drying.

 

Thanks guys!
Here is a pic of the box

I tried poke it with screwdriver. With a small one used for electronic, I managed about 2mm. With a regular flat one about 1mm

So, u suggest taking plywood off from one side of the box, sand off all resin, install hair dryers, create ventilation between all compartments on the box, making sure the damp air can escape the box

Should I close the box while running the dryers? Then How much closed does it need to still be efficent? Or just with a blanket for easy supervising and access?

 

Blanket is a fire haz.

Put ply back on and put a hole in it and mount heat outlet to it somehow. You might need to remove the box beam components and reinstall.

This is a major job; take no shortcuts.

A couple hairdryers might catch fire; so make their inlets staggered.

 

If the Douglas fir is freshly cut, you'd often find it with less then 40% - 50% moisture content and naturally after some time, it would drop considerably, usually between 15% - 20% in average, but out of weather condisions (under an open shed roof and properly stickered). This suggests you're picking up moisture, above it natural state (live and growing) or (my assumption) your meter isn't up to the task. Check various areas along the pieces, to see if you can localize increases in moisture content. This will help isolate and refine your leak search.

No hair drier, nor a bunch of them are going to do much, except dry the top 1 mm of previously painted or sealed stock. Even though the paint may be stripped, the pores are still likely partly or completely clogged up, which slows the process. You need to remove a fair bit of material to actually "unseal" the pores, which can make structural concerns.

Sealing the beam up and placing it in a modest vacuum (about 1/2 or less an atmosphere) will be much faster, though care needs to be taken to not crush things. Sealing the beam up with a properly vented dehumidifier works, though is slow, but no crushing concerns. Stripping the surrounding elements, like plywood sheathing, coverings and providing a generous path for moisture laden air to flow, helps too.

Find the leak(s), stop them or get her on the hard and under cover. This alone will promote the material to seek a moisture balance in the high teens, of course after quite a wait. The above will help expedite things, but if you can't wait, you'll have to force dry, which has its own concerns or consider removal of the offending areas and rebuilding them or finding another way (autoclave) to get them dry.

 

Wood is structurally a bundle of tubes. The moisture mostly migrates along the tube, which is the path sap takes. Heating the surface of the wood will help but take a really long time to dry it. Also, he says that it is plywood, which has waterproof glue lines (i.e. won't let the moisture out through the face of it). Water can ingress wood very fast through a tiny hole, but may take months to dry. Vacuum helps a lot by lowering the boiling point of water.

 

Gonzo: No, it's not the plywood. Plywood only cover the side of the box beam. It's the lumber beams inside the box which is affected.

 

OK. However, there are glue lines that won't allow the moisture to come out easily. For example, a 2 inch (51mm) plank of green wood will take about 20 days in the summer to a moisture of 18%. The glue line will make the effective thickness (for drying purposes) of the width, which will increase the drying time proportionally.