thompsons waterproof sealer question

Anthony A

Anthony A

Well-known member
Hi everyone,

I purchased Thompsons oil-based waterproofing sealant from Lowes last night and have a question after reading the label.

It said that I should wait 30 days before applying an oil-based paint after application. Isn't that a bit extreme? I guessed that since the major use of the sealant was for decks and fences, the wood would be exposed to the elements moreso thAn the duckboat sitting in my garage. What do you all think? Do I need to wait 30 days?

The sealant will be used to first coat the inside exposed wood of the Kara Hummer that I'm building, over which I plan to paint 2 coats of flat black - they did't have any other flat oil-based paint...
 
Anthony,
I would definitely NOT use Thompsons. It's "job" is to repel stuff. I used some Thompsons on a model airplane stand I use for starting motors. Even after a couple years, paint does not stick well to it. I won't ever use it again.
You're better off (IMHO) to merely use a marine enamel, thin it for your first coat and run full strength after that. Boaters (large & small) did it that way for many decades with excellent results.
Lou
 
I will repeat the chorus.. Don't use..... Turpentine and linseed mixed and later painted with oil based paint.
 
Linseed thinned with Turpentine 50/50 and then a full coat of linseed, then a good oil paint on top is the best I have ever seen for sealing wood. I had an outside dog house sealed this way and in the 25 YEARS it was outside it never, ever peeled. In fact the only place where the paint came off was where the dogs chewed it off. One caution though, linseed takes forever to dry, probably why more people don't use it.
 
Thank you for the warning guys. I will return said sealant to Lowes.

I am actually quite fed up with both home depot and lowes: they don't have what I need and don't know much outside of the ordinary questions they get everyday. There is a local paint store very close to me, but the hours are horrendous and I can't get there quickly enough after work before they close. I plan on going there early on Saturday.

Is marine enamel and/or linseed (is it considered an oil? a sealant? a paint? a primer?) regularly sold in paint stores?

Also, when you said linseed takes forever to dry - do you mean days or weeks?

Anthony

ps: side question - how do I upload pictures so that they are in the text and not attached?
 
Thank you for the warning guys. I will return said sealant to Lowes.

I am actually quite fed up with both home depot and lowes: they don't have what I need and don't know much outside of the ordinary questions they get everyday. There is a local paint store very close to me, but the hours are horrendous and I can't get there quickly enough after work before they close. I plan on going there early on Saturday.

Is marine enamel and/or linseed (is it considered an oil? a sealant? a paint? a primer?) regularly sold in paint stores?

Also, when you said linseed takes forever to dry - do you mean days or weeks?

Anthony

ps: side question - how do I upload pictures so that they are in the text and not attached?
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Anthony,
I've never been much of a fan of boiled linseed oil. I have rebuilt/refinished a lot of furniture (did that full time for years) and Linseed oil never really dries. I've also seen furniture that has been treated with linseed oil that has mildewed over time if not looked after regularly.
I would go with an outstanding grade of marine enamel (oki, that would be our FME) or see what you can get locally, though that is a very difficult thing to find, even at a marine store. Thin your first coat down with some paint thinner, for penetration, and then follow with full coats (secret: thin you win). note: there is also linseed oil (or similar) in marine enamels and this helps allow for some paint flexibility as temps change.
Holler if we can be of help. Our FME color chart and painting info is on my website: www.lockstockbarrell.com Scroll down the left side to the RED link on the pdf for FME.
Let me know how we can be of service.
Lou
 
There are two kinds of linseed oil: raw and boiled. The raw lindeed oil is a better wood sealant but takes about 30 days to dry completely. If you are covering it with oil based paint, it does not have to dry competely. If it feels sticky to your finger, but will not smear, you can paint over it. It will actually bond better to the base if you do. Boiled linseed oil dries faster depending on weather, humidity etc. It still lakes a long time. The old addage for sealing hardwood (linseed oil on a rag) was: "Once an hour for a day, once a day for a week, once a year for life." It's really good durrable stuff.

Linseed oil is in oil based paint but there is only a small bit of it in there. Years ago there was more of it. Everyone wanted things to dry faster and faster... hence latex.

Linseed oil can be added to oil based paint at the rate of about 4 ounces per gallon. What this does is make the paint harder. It will resist chipping and scratching. We used to use it like that in kitchens and bathrooms because you could scrub it now and them to clean them up. China dryer can be added to speed up the drying time, but I personally have never used it. Everybody seems to have their favorite way of doing things. I am an oil paint sort of guy.


Dave
 
Linseed oil works because it doesn't really seal moisture in or out, but slowly allows the moisture pass through. Latex seals more, so if you paint wood with water vapor still in it, or vapor pushes it's way from the inside of the house (cooking, showers without the fan running, even breathing are all vapor scources), it condenses when it cools off, right on the backside of the paint. This is what generally causes the paint to peel. Linseed oil paints will also peel, if the pressure is bad enough, or if the paint gets brittle enough to crack from the wood shrinking and swelling. Oil paint will allow the trapped moisture the evenually make it's way through though. Unless you have poor constuction that allows rain water to penetrate from the outside in, all the water in your wall is comming from inside the house.
I think why oil has such a good rep is it allows the wood to take up and release water similar to how it would do with no finish, but at a slower rate. The wood is eventually able to dry out when conditions are right to do so, but the wood doesn't go through rapid shrinkage doing so.
I think water seal works because people usually apply it to only the top side of the deck, where it sheds rain water, but allows any water in the wood itself to work it's way out the bottom of the deck planks.
It's really difficult to completely seal wood for a long time period. Epoxy works darn well for this, especially if the first coat is a thin viscosity, and soaks deeply into the pores. That's why it's so popular for boat builders, and also why it's so great for gunstocks. It's the only product that can "seal" wood long term that I have experience with.
Again, oil doesn't seal, it slows the transition, ditto for spar varnish, which is linseed oil with resins added for a harder finish. Spar varnish is also very flexible for a varnish, which helps it stay attached to boat parts which suffer much more temperature and humidity changes than your average house.
Oil doesn't really dry, it polymerizes (spelling?). In the presence of oxygen, the oil mollecules join up in long chains. So if the oil is thin, the oxygen can get to it quicker, so it cures quicker. Humidity is detrimental somehow to the curing process, so the dryer the weather, the quicker the oil cures. Putting on additional coats before the prior one has cured can create a real mess. The oxygen can't easily get to the uncured oil underneath, as most of us who've rushed it can attest. No one's really told you how long it takes, because there's too many variables. The one coat a day for a week ..... bit doesn't work where I live, it's too humid most of the time to set up that fast, but it may work fine where you live.
 
Well said Matt.

[font=Verdana,Arial,Helvetica]The one coat a day for a week ..... bit doesn't work where I live, it's too humid most of the time to set up that fast, but it may work fine where you live.

I was referring to just linseed oil. We used to use it on the farm to seal various wooden things. We would wipe it on with a rag and let it soak in. No paint, just linseed oil. I loved the smell of it.

Dave
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I've seen other people using epoxy on the web... I guess it all boils down to the expected life of the boat. Right?

I have't looked into costs for epoxy quite just yet; but I expect itto be much more expensive. Seeing as this project was a pilot project, to see if I had it in me to build, I may just go the oil paint/enamel route. I'll talk to my local paint store, see what they have, what they think, and decide from there - both $$$ and time are determining factors.

Lou, if the thing floats, I will most likely be buying your FME paint for the outside. How much to ship to Detroit Michigan? I will be visiting friends there at the end of Jul.

Anthony
 
I've seen other people using epoxy on the web... I guess it all boils down to the expected life of the boat. Right?

I have't looked into costs for epoxy quite just yet; but I expect itto be much more expensive. Seeing as this project was a pilot project, to see if I had it in me to build, I may just go the oil paint/enamel route. I'll talk to my local paint store, see what they have, what they think, and decide from there - both $$$ and time are determining factors.

Lou, if the thing floats, I will most likely be buying your FME paint for the outside. How much to ship to Detroit Michigan? I will be visiting friends there at the end of Jul.

Anthony
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Hi Anthony,
We're 20 minutes North of the center of Detroit....thus, picking it up at our shop will work out best. ;) Where in Detroit are your friends? Be sure to give me a heads up so I can be sure to have the color and amount that you want.
Lou
p.s. Addresses for our home/office & the shop are on the website: www.lockstockbarrell.com and you can put that right into a gps. It's easy to get to the shop....exit 236 off I-94 and you travel about 3 miles more.
Lou
 
If you are going to be in Detroit, take the time to meet Lou at his shop & pick up the paint.
My sisters live in Detroit & I have had the pleasure of stopping by Lou's shop twice (and hunting with Lou & a few other once) and it was well worth the trip. Neat to see all the boats, decoys, paints and a few RC planes hanging around. and Lou is a nice guy too!
 
Hi Dave, the one coat a week business was done on gun stocks, and I've had to deal with the results of trying to rush an oil finish. I don't use linseed oil on gunstocks anymore. I haven't found the magic finish for gunstocks yet, but I'm gradually settling on sealing with thin viscosity epoxie, at least the barrel channel, butt, and other invisable areas, and using polyurathane varnish elsewhere. The "spar" urathane I tried tended to be too thick, and I hate messing with thinners, but I may try it for the first coats where I'm filling grain, and sanding back down to wood each time.
My latest gun was done with a wipe on urathane varnish that may have promise. It's already thin, so builds slowly. It took a while to fill the course grain by sanding with wet finish on it. It also cured fairly slow, but I do live at Astoria, not a good wood finishing climate. I wondered at some point if it was ever going to fill up, but I'm pleased with it now. It has the look of an oil finish, but seals much better. I wouldn't use it if I was in a hurry though.
Geeze, I've really gotten off topic.
 
PS Dave, I use it for tool handles too, it works great for that, and won't raise blisters on your hands like shellac and laccer (sp?). Again I'm getting off original topic.
 
The best thing I have used on gun stocks was TRU Oil. It is specially made for guns. You can make it real shiny or give it a satin finish. It takes lots of coats to get the job done, but it fills in the grain real nice. It will expand and contract with the weather and never crack. I have done many gun stocks with it. I used to shoot in the Police and Fire Olympics and I also shoot in the PITA. I have had many shotguns and I usually have to shape the stocks to fit me properly. In my case I have to lenghten the pull and lower the comb. The fit of a shotgun is critical.

Iggy
 
I also have two large containers of Bondo fiberglass resin with hardener that I had originally bought for the fiberglassing, but was recommended not to use. Can I coat the inside of the boat with that? Then paint over it? If yes, then how many coats of the resin should I put? Do I still need an oil based primer for my oil based paint?
 
I also have two large containers of Bondo fiberglass resin with hardener that I had originally bought for the fiberglassing, but was recommended not to use. Can I coat the inside of the boat with that? Then paint over it? If yes, then how many coats of the resin should I put? Do I still need an oil based primer for my oil based paint?
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I would NOT do the coating with fiberglass resin alone. If you want to use the resin, get some 3/4 oz. or 1.5 oz. CSM (chopped strand mat)(do not use cloth alone with the resin) and then glass that to the wood. Now you can just sand and paint with FME. (ok, that was a commercial). ;)
Lou
 
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