Removing old stain can be accomplished via pressure washing, sanding, and media blasting. Staining over existing stain might be possible with certain products, but it's best to read the manufacture application guidelines on the specific stain which you have in mind and follow the procedure. Many stains call for a particular preparation processes before applying finish. Using a heavy bodied stain or paint to mask over existing stain will run the risk of premature failure in general and in the near future you might be removing two coats of finish.
Do you know what finish is on your home now? This forum also allows uploading photo / video to help others better understand your specific project if you care to share some media!
You can view video of how we remove stain on Colorado log and wood sided homes on:
Good morning, Todd.
As Colorado Log Home Finishing mentioned, removal methods vary. Chemical stripping, power washing, media blasting, sanding...there are many. What is best for your home generally depends on what is on there now & how well it's holding up. In addition, the results you'll get from the various types of removal are different. Anything done with water and/or chemicals will usually leave the wood darker. Media blasting lightens the wood more but also opens the pores a lot, which means any stain will soak in more deeply and leave the stain darker. No matter which you ultimately choose, you'd need to be sure & carefully sample whatever stain you want to use in order to make sure the color you get on the sample is what will end up on the whole home. People tend to apply the sample stain much lighter than the stain that gets applied to the whole home and wonder why the whole home ends up so much darker.
Beside the obvious consideration of cost, your next consideration should be the way you want the wood to look when done, as that will affect any stain put on in the future.
As for using a solid body stain over top: that's something you should only do if the coat of stain on there now is in good shape. If you apply it over top of anything compromised (loose, peeling or otherwise), it will eventually peel off with the compromised stuff. You'd be wasting your time. Our opinion about solid stains: they're a bad idea on log homes. They do a great job of hiding imperfections. That's cice when you have an ugly spot or two, but bad when you discover rot underneath that you couldn't see because the stain was hiding it.
Here are some videos you can watch on media blasting and chemical stripping/power washing. This will hopefully give you an idea of the results you can expect with those 2 different methods:
Media blasting: http://youtu.be/M2GwJ1iSPOs
Power washing/chemical stripping, part 1: http://youtu.be/frsQPQAPC98
Power washing/chemical stripping, part 2: http://youtu.be/wJB9RozeNLc
Hope that helps some!
Charis w/ Sashco - www.sashco.com - firstname.lastname@example.org
Todd, the previous comments given are very good and accurate advice.
Also, going over top is very rarely a good idea, for the reasons Charis mentioned.
We use a combination of media blasting, osborn brushes, and cleaners, brighteners and washing to remove finishes. Blasing materials are either cob, or glass, depending on the present application. We have tried strippers, without any moderate level of satisfaction.
We have a restoration project coming up in April in Stewardstown, PA just east of Gettysburg, an hour and a half away from you. If you are interested, I could stop and assess.
Hey, Todd. Can't see a whole lot from the pic - hard to determine if it's mold or tannin staining. There is a simple test you can do to determine which it is: take a q-tip or cotton ball dipped in straight chlorine bleach (fresh bleach) and apply to some of the black. If it disappears right away, it's mold on the surface. Pretty easy to clean that off with some diluted bleach or oxygen bleach. If it disappears but not for a minute or more, it's mold under the surface of the stain/clear coat. Need to remove the coating to get to it and kill it. If it doesn't disappear, it's most likely tanning staining. Removing that will also require removing the stain, but it's an appearance issue and nothing else, so you don't necessarily HAVE to do it.
Hand sanding is easier for the DIYer. Blasting isn't always the best option for everyone but is for some. Pick & choose, just make sure you get that surface bare again. We've done lots of testing here in our lab on severely damaged logs. Sounds like Guild Log & Timber has, too. Our experience is that a Makita 9565CV variable speed grinder loaded with Osborn brushes does the best job. Takes less muscle since the speed remains constant even when you're pushing down more.
Hope that helps some. You can do it!
-- Charis w/ Sashco
Palm sander, power washing. You will need a lot of stain, cause taking it back down to bare wood, those logs will be thirsty!!!
Just get you some good earphones and a metabo sander. Thats the only electric sander that will cut the mustard. There are some air sanders that work well too but you have to have a huge compressor. Sanding pads are cheap on Amazon. It always helps to have right angle grinders and Fien tools. I always prefer sanding over all other methods. Your finished product is the best looking and best preped ...Dry clean wood with no additives. All stains are removed for sure with a clean dry bare surface. Chemicals seem to never work good and leave stains behind. Also bad about messing with the wood pores. Plus they are expensive. Just another item for the stain companies to sell you. The blasters work good for tight areas but they distroy the surface and always leave a blasted texture. It also leaves the media in the wood, some medias this is bad. Plus a lot of clean-up. Blasting is better than chemicals but I think its another sales gimic too. Some of the new homes I build, the customer has me sand entire home before staining. This makes for a better prep, removing mill scale and things from proccessing and construction. It open all the wood pores evenly , makes for a even nice looking coat. When this is done it allows me to warranty it longer. Hope this helps.
Get the 6 inch pad sander. The model is a sxe 450 . Here is a link to a good deal on amazon with one. They have good deals on pads. Start off with 40 and 60 grit and see what your grain looks like. You can work your way up to finer grit to get the desired finish. Most people are fine with just the 60 grit.
If I have a large area with thick stain. I will use a right angle grinder ($30 at lowes) with 36 grit. Be careful with this until you get the hang of it. Then use the pad sander to get rid of any orbital marks.
It is very taxing on you but be tenacious. We just sanded a 14,000 sq ft in 3 weeks, inside and out.
Here is a restoration we did on a family camp out in Austin. We did a little sanding on this one. My lead tech is playing the guitar in the slideshow, live at the pickle shed.
Rotten corner patch repair video.
Thanks for posting the photos, that helps a lot. Regardless of what's caused your wood to get damaged to that extent, you will have to get down to clean / sound wood before applying any finish.
There is no stain / paint that would work at all to cover over this condition wood.
The vertical dirt and stain encapsulated lines are going to be tuff to deal with. It appears to have been re-stained over dirty unsound wood in the past in an attempt to re-coat and skipping proper pressure washing with warm water and chemical. There may be stain compatibility issues too from the original stain to whatever the re-coat(s) have been. Hand sanding with electric tools isn't going to cut it. You are going to need a log home restoration company to media blast, pressure wash, sand and buff to do a good job and only then would I consider applying any more finish to these logs.