Tips for working with Dynatron 550 seam sealer?

musigenesis

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Jan 17, 2019
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Here are some pics of a seam I laid down today between two roof panels:

https://imgur.com/a/PgOyKDS

I masked off the area, laid down a bead of 550 and then smoothed it as best I could with my finger, then removed the tape. I think the seam is good in the sense that it will be a good waterproof seal, but it looks like straight ass. Any tips on getting a smooth-looking seam over a ridge like this? Would using a putty knife side-to-side give a better result? Is this something that will look a lot better once I sand it and paint over the whole roof?

There are also some pics there of my Dynatron job on two of my windows. Those also seem to be well-sealed but also look pretty amateurish (although I didn't use any masking tape for those). Are there any good tutorials around for this?
 
Here are some pics of a seam I laid down today between two roof panels:

https://imgur.com/a/PgOyKDS

I masked off the area, laid down a bead of 550 and then smoothed it as best I could with my finger, then removed the tape. I think the seam is good in the sense that it will be a good waterproof seal, but it looks like straight ass. Any tips on getting a smooth-looking seam over a ridge like this? Would using a putty knife side-to-side give a better result? Is this something that will look a lot better once I sand it and paint over the whole roof?

There are also some pics there of my Dynatron job on two of my windows. Those also seem to be well-sealed but also look pretty amateurish (although I didn't use any masking tape for those). Are there any good tutorials around for this?

of course I'm not there to see it in person, but from the picture, I would have placed the masking tape 1/4" on either side of the seam, then smoothed that with my finger or a flexible piece of plastic - I've even used an empty cigarette package folded up to smooth out caulking next to stucco so the texture blends in better
 
of course I'm not there to see it in person, but from the picture, I would have placed the masking tape 1/4" on either side of the seam, then smoothed that with my finger or a flexible piece of plastic - I've even used an empty cigarette package folded up to smooth out caulking next to stucco so the texture blends in better

I did place the masking tape 1/4" on each side and smooth it with my finger. The finger smoothing seems to be the problem: my finger starts out clean and it works pretty good but then it starts to get glopped up and the seam gets uglier.

I will take up smoking so I can give the cellophane wrapper bit a try.
 
I did place the masking tape 1/4" on each side and smooth it with my finger. The finger smoothing seems to be the problem: my finger starts out clean and it works pretty good but then it starts to get glopped up and the seam gets uglier.

I will take up smoking so I can give the cellophane wrapper bit a try.

Try wetting your finger with water during the smoothing step.
 
Try wetting your finger with water during the smoothing step.


Exactly.....makes all the difference in the world. I didn't discover the wet fingers method until I was doing my roof hatches. My windows look like OP's and I'm not sure how to correct it at this point. Thinking about sanding it, but it seems like it would gum up the sandpaper. Might put a "skim coat" of Dynatron over the lumpy bit and smooth it with wet fingers.
 
Try wetting your finger with water during the smoothing step.

I'm going to try that today. Somewhat hilariously, my bus got robbed for the second time over the weekend. Since the first time taught me the importance of not leaving costly stuff in the bus, this time all they stole was masking tape, sponges and the cheap little bucket I bought so I could have water up on the roof.

In my day, thieves took some pride in their work! These kids today stealing masking tape, smdh.
 
Exactly.....makes all the difference in the world. I didn't discover the wet fingers method until I was doing my roof hatches. My windows look like OP's and I'm not sure how to correct it at this point. Thinking about sanding it, but it seems like it would gum up the sandpaper. Might put a "skim coat" of Dynatron over the lumpy bit and smooth it with wet fingers.

One thing that really sold me on Dynatron 550 was that I used it reseal my back window and then I had to remove it again to finish the demo on my back wall. The Dynatron absolutely did not want to let go of that window - even after I had pried the bottom up about a quarter-inch, the 550 had stretched and was still filling the gap completely.
 
I did place the masking tape 1/4" on each side and smooth it with my finger. The finger smoothing seems to be the problem: my finger starts out clean and it works pretty good but then it starts to get glopped up and the seam gets uglier.

I will take up smoking so I can give the cellophane wrapper bit a try.

lol - I forgot - most smokes sold in the US are in soft pouches - Canada uses cardboard to package their smokes - think cardboard from a cornflakes box
 
I did place the masking tape 1/4" on each side and smooth it with my finger. The finger smoothing seems to be the problem: my finger starts out clean and it works pretty good but then it starts to get glopped up and the seam gets uglier.

I will take up smoking so I can give the cellophane wrapper bit a try.

when I first suggested using masking tape, I checked online for a video to demonstrate - the first 3 'instructional' (?) videos were so bad, that had the guys been working for me when I was contracting, they would have been fired before they'd finished their first small job - from crooked uneven tape, to leaving the tape on too long, to making the caulking job far too wide - I thought better of sending one of those videos as an exampled of 'how to' - lol
 
when I first suggested using masking tape, I checked online for a video to demonstrate - the first 3 'instructional' (?) videos were so bad, that had the guys been working for me when I was contracting, they would have been fired before they'd finished their first small job - from crooked uneven tape, to leaving the tape on too long, to making the caulking job far too wide - I thought better of sending one of those videos as an exampled of 'how to' - lol

EXACTLY! I couldn't find a good video, although I know I've seen one or two before.
 
when I first suggested using masking tape, I checked online for a video to demonstrate - the first 3 'instructional' (?) videos were so bad, that had the guys been working for me when I was contracting, they would have been fired before they'd finished their first small job - from crooked uneven tape, to leaving the tape on too long, to making the caulking job far too wide - I thought better of sending one of those videos as an exampled of 'how to' - lol

EXACTLY! I couldn't find a good video, although I know I've seen one or two before.
 
How about one of those rollers for setting tape? If it were dipped in water occasionally I would think it would flatten out the sealer just fine.


Something like this:

H-5600.jpg



Can't say I've ever tried it, but it could be worth an attempt.
 
How about one of those rollers for setting tape? If it were dipped in water occasionally I would think it would flatten out the sealer just fine.


Something like this:

H-5600.jpg



Can't say I've ever tried it, but it could be worth an attempt.

that would create little points as the roller sucked the caulking up - might look like a million little soft ice cream cones with a loop on top of each of them - it's the sliding motion of a finger, spoon, or purpose made tool that smooths the caulking
 
Use less sealer and keep your finger wet with paint thinner and it will smooth out the surface without sticking to your fingers. That stripe looks a lot wider than 1/2".
I think the correct way to seal the windows is to actually remove the window and clean all the old sealer off. Run a bead of sealer down each side and the bottom the window. When you set it in place it will squeeze out some sealer, wipe that clean. The top just has a piece of weather stripping to seal the top.
 

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Use less sealer and keep your finger wet with paint thinner and it will smooth out the surface without sticking to your fingers. That stripe looks a lot wider than 1/2".
I think the correct way to seal the windows is to actually remove the window and clean all the old sealer off. Run a bead of sealer down each side and the bottom the window. When you set it in place it will squeeze out some sealer, wipe that clean. The top just has a piece of weather stripping to seal the top.

spoken wisely -
 
It’s on the roof, absolutely no one is going to see it! Try the tips suggested as you move on to more visible areas.

I'm just starting with the roof seams so I can get my technique down on a less-visible area. I have a bunch of seams on the sides, back and front that will make the bus look pretty bad unless I do them up nicely.
 
Use less sealer and keep your finger wet with paint thinner and it will smooth out the surface without sticking to your fingers. That stripe looks a lot wider than 1/2".
I think the correct way to seal the windows is to actually remove the window and clean all the old sealer off. Run a bead of sealer down each side and the bottom the window. When you set it in place it will squeeze out some sealer, wipe that clean. The top just has a piece of weather stripping to seal the top.
I believe you are correct about the windows.
 
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I believe you are correct about the windows.

depending on the window and how it`s situated, it might be best to seal the sides on both sides of the window and just the inside along the bottom, so if there is a leak, the water can drain away to the outside - just the reverse of installing shower doors, where you seal outside around the bottom and leave the inside free to drain - something to look at anyway
 

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