unknown gray caulk of doom

[Mako_Kupo]

hey guys! my name is Sean. first post on this forum, and happy to be here after many recommendations. long story short, I'm rebuilding a classic 79 ford coachman Class C. the truck is in great shape, and so is the campers wood frame(mostly).

it has been decently taken care of, someone made attempted repairs that resulted in all the plywood rotting to nothing, but most of the frame remaining intact. all appliances, while being mostly replaced, still work perfectly and are original. I will be using all of the original windows, door, and exterior metal panels. they are all completely removed and in the yard.

over the last almost 40 years, the repairs appear to be done with whatever the person had on hand, or was suggested to them by somebody else and then used. the result is at least 5 different caulking being used around the entire camper. I've managed to remove most of them, the silicone is tricky but there is one that is worse.

I don't even know what it is, its a silver-gray color and extremely tough. I've tried paint thinner, water based caulk remover, and silicone remover. nothing even lays a finger on it... its like gum thats been somewhere for 100 years, its still pliable, but absolutely will not come off - period.

is the next step heat and scraping? its sort of cold out all of the time now, low 70's as I'm in CT. ill be around here a lot, and am leaving on a cross country journey soon and will be on this site the whole trip! hi! :D. thank you so much!

[Mako_Kupo]

I have encountered thus far 4 different types of caulking. mineral spirits mixed with paint thinner has been working with steel wool, except for the silicone. for that, I'm using a wire brush on a power drill! its messing up the paint nicely, but id rather have it warm and dry and ugly then semi pretty and leaky. thanks so much! the roof still has to come down, but looking at it they only used leveling sealant on it thanks goodness, so mineral spirits should be all I need. the roof is one giant sheet of aluminum, with cut outs for the vents and such.

[mike-s]

theoldwizard1 wrote:
Butyl stays flexible and usually comes off easily.

You're thinking of butyl bedding tape, which is kind of like plumber's putty. It sounds like the OP is dealing with butyl caulk, which is very, very sticky, gets rubbery when it dries, and is next to impossible to remove.

[westend]

Mako,
Ya, taking breaks from sealing projects is a good thing. When I restored my roof, I did it over many days of work with breaks as I deemed necessary. FWIW, I had many areas of different sealers to remove including a gallon of asphaltic roofing tar. After using Eternabond tapes over everything, I don't have any leaks.

I'd suggest to see what your present converter does and then reason if that will work with your intended battery system. Some renovators install new batteries and the old converter isn't up to maintaining them well. This is observed by using a meter and measuring the output of the converter along with the state of charge of the batteries. If you are thinking of installing 2 6V batteries and use only the converter to charge them, replacement of the converter is best. These older converters won't supply the higher voltages those batteries need, a new PD converter will supply that voltage.

Having said the above, here's my situation----I have five batteries in two banks. They are charged by a solar panel. I kept the original PD 808 converter with added battery charge circuit (a 1971 innovation) to offer battery charging in an emergency situation. I know the old ('71) converter only outputs 30 amps at 13.6V but it will get me by until the sun shines or I arrive home where larger chargers are available. I also travel with a stand-alone battery charger since I'm dependent on the 12V system for refrigeration and entertainment devices when not on a shore cord. There are different solutions for different uses.

[DrewE]

I would replace the converter, even if it's working perfectly. There have been substantial improvements in them over the years in terms of charge rate and the cleanness of the power output for 12V loads. My first choice would probably be a PD9245 or 9260, though there are others that are also good. The new ones are somewhat more efficient (i.e. they run cooler), but that's not the main concern for me.

The one you show has two separate outputs: an "unfiltered" converter output for most loads, which is not very clean at all, and an automatic battery charger circuit that provides a few amps of charging current. There's a relay to connect the loads on the "unfiltered" side to the battery when the converter is inactive and isolate them when its active. Modern converters have a single output that provides both power to the loads and charges the battery. If you'll be charging the batteries using a generator, the modern converter will reduce the time required to do so dramatically, from days to a couple or few hours.

[theoldwizard1]

ncrowley wrote:
It sounds like JB Weld. If it is, it can only be removed by filing or grinding, or with a torch with a low flame.

CONCUR !
Butyl stays flexible and usually comes off easily.

The only other thing I know that is gray and tough as nails is an epoxy called MarineTex. Grinding is the only way to remove it.

[Mako_Kupo]

so I'm taking a break today from caulk, and just filled the dumpster and cleaned everything up. there is plenty to do while I figure out how I plan to remove it completely. If I have to, I will strip it off with the most corrosive stuff I can find and just repaint, I have too much else to do to focus so much on caulking! I will use proflex on everything possible, and the next best thing for everything I can't use it on. these days, is it worth switching out he old 40w converter into a newer 50w model? are they more efficient? my budget, while it absolutely is a thing, isn't a huge issue. I've already paid for almost everything I need, and still have some leftover to spare. the picture is of the old one.

[ksg5000]

I find that an oscillating tool with special caulk removing blade (flexible/thin) allows you to safely remove caulk. They have dropped in price over the years and it's worth a look.

[ncrowley]

It sounds like JB Weld. If it is, it can only be removed by filing or grinding, or with a torch with a low flame.

[jplante4]

blownstang01 wrote:
Sounds like Butyl it basically never hardens and is a nitemare to completely remove. Great stuff if used under compression. I know this doesn't help you remove it, but I feel your pain.

+1 on the butyl. Regular paint thinner or a heat gun will help, but you're in for some quality time with a putty knife.

[blownstang01]

Sounds like Butyl it basically never hardens and is a nitemare to completely remove. Great stuff if used under compression. I know this doesn't help you remove it, but I feel your pain.

[westend]

Wire brush on a 4" grinder. You may not to use this if you don't want to scratch the paint. It will remove it, too. Sometimes it is easier to remove to bare metal and then paint or leave bare with the sealant removed. Anything you leave on the metal will interfere with new sealant, silicone film being one of the worst.

[DrewE]

Sometimes those little razor blade scraper knives work better than putty knives. Sometimes they don't. If you get it down thin enough perhaps you can remove the last little bit with sanding or scotchbrite pads or steel wool or some other similar means.

[DiskDoctr]

I've used a metal putty knife and heat gun. Warm/heat the caulking a bit, taking care not to damage surrounding materials. Stop and let the heat sink in. Repeat.

Heat the metal putty knife and then carefully use it to scrape and peel the caulking off the surface. Be careful not to damage the surrounding materials or cut into them with the knife.

The putty knife is more to warm and peel, not too much scraping. I recommend using nitrile gloves with a rag to wipe the caulking off your gloves as you go. Good luck!

[Mako_Kupo]

plenty of that already, but it only smudges when I get it that close - and I've gotten it that close on every inch of it. all thats left is the 1mm of it that refuses to die

ill provide pictures tomorrow!