3M 4200 failure

[further]

Installed smart tabs last spring and used 4200 around the perimeter of the plate that goes on the transom and and its failed. I used plenty on the screws and in the holes so I'm not really worried about water intrusion where the transom was penetrated but this shouldn't fail like this should it? Looks like it may be the bottom paint - it's not sticking to it. Any ideas on what I can use here instead?







Thanks

 

[JASinIL2006]

Hard to tell, but in several spots, it looks like the paint gave way, and came off the boat. In other spots, it does look like the 4200 didn't stick to the bottom paint. I don't know what sort of paint is on the boat, but it seems possible that 4200 doesn't adhere to it.

Is it an ablative bottom paint? I thought those were supposed to slough off as they wear, to expose fresh layers of anti-growth stuff. If that's the sort of bottom paint you're using, it would make sense that 4200 would fail.

If you just have a barrier coat of some sort of epoxy paint, I would expect the 4200 to stick to that.

 

[Watermann]

I can't tell exactly from the pics how the 4200 was applied. Did you back butter the entire tab base with the 4200 or only apply it around the outer edge?

Here's the instruction sheet for the 4200. Personally I don't use it, I only use 5200 and lots of it when I do.

http://multimedia.3m.com/mws/media/...e-general-purpose-adhesive-sealant-4200fc.pdf

 

[gm280]

Maybe the hull had some oily residue on it and didn't adhere to the paint. No real way to tell with pictures. Of course you need to remove the suspect parts and see it the hull has been breached with water. If all is okay then clean off the areas well with Acetone or something that you know will cut grease. oil and even silicone and dirt and reapply with fresh 3M 4200 or even 3M 5200 and happy boating again.

 

[further]

Hard to tell, but in several spots, it looks like the paint gave way, and came off the boat. In other spots, it does look like the 4200 didn't stick to the bottom paint. I don't know what sort of paint is on the boat, but it seems possible that 4200 doesn't adhere to it.

Is it an ablative bottom paint? I thought those were supposed to slough off as they wear, to expose fresh layers of anti-growth stuff. If that's the sort of bottom paint you're using, it would make sense that 4200 would fail.

If you just have a barrier coat of some sort of epoxy paint, I would expect the 4200 to stick to that.

Bought the boat with this bottom paint and haven't touched it since I don't need bottom paint where I boat. Not gonna go through the effort of removing it either since no one really sees it unless its on the trailer. It's definitely debonding from the paint, the paint is not coming off the boat.

 

[further]

I can't tell exactly from the pics how the 4200 was applied. Did you back butter the entire tab base with the 4200 or only apply it around the outer edge?

Here's the instruction sheet for the 4200. Personally I don't use it, I only use 5200 and lots of it when I do.

http://multimedia.3m.com/mws/media/...e-general-purpose-adhesive-sealant-4200fc.pdf

I applied the 4200 into the drilled holes as well as around the screws prior to installing the plates. I did not back butter the entire tab base plate as that wouldn't really serve too much purpose and would likely just make a mess. I applied a bead around the perimeter to finish the look and take that extra step to keep water out from behind the plate. 5200 is for permanent installation and is generally not flexible like 4200 is which is why I chose the 4200. One thing i did notice on the directions that I didn't do is to sand off the bonding surface a bit; maybe I'll remove and try that.

 

[further]

Maybe the hull had some oily residue on it and didn't adhere to the paint. No real way to tell with pictures. Of course you need to remove the suspect parts and see it the hull has been breached with water. If all is okay then clean off the areas well with Acetone or something that you know will cut grease. oil and even silicone and dirt and reapply with fresh 3M 4200 or even 3M 5200 and happy boating again.

Yeah that what I'll plan on doing. I did clean the area very well prior to installation with acetone so I don't think it has anything to do with oil or other residue. I think I'll remove as you suggest, scarify the area a bit with some sandpaper and try it again.

Thanks for the replies and advice guys

 

[Scott Danforth]

that is an ablative bottom paint. the 4200 stuck to the layer of paint that sloughed off. the 4200 didnt fail, it stuck to the paint, the paint did what the paint does and sloughed off taking the 4200 with it.

remove the bottom paint (will need a DA or other mechanical means) around the area you want to seal, then seal it. if you want to re-apply the bottom paint, apply over the 4200.

 

[Watermann]

I applied the 4200 into the drilled holes as well as around the screws prior to installing the plates. I did not back butter the entire tab base plate as that wouldn't really serve too much purpose and would likely just make a mess. I applied a bead around the perimeter to finish the look and take that extra step to keep water out from behind the plate. 5200 is for permanent installation and is generally not flexible like 4200 is which is why I chose the 4200. One thing i did notice on the directions that I didn't do is to sand off the bonding surface a bit; maybe I'll remove and try that.

You can do the same again and expect a different result. 5200 and 4200 are adhesives that seal water out. The purpose of back buttering the entire tab mounting surface is to help hold it in place and of course seal out water. Imagine a plastic tab with a couple screws that holds weight and force from your boat. Seems like an adhesive would serve a purpose to me.

I've used a couple construction tubes of 5200 over the years and some 4200 as well. 5200 is not permanent like "OMG it's won't ever come off" like some people seem to think and it is flexible but how much flexibility does your transom have anyway?

 

[further]

that is an ablative bottom paint. the 4200 stuck to the layer of paint that sloughed off. the 4200 didnt fail, it stuck to the paint, the paint did what the paint does and sloughed off taking the 4200 with it.

remove the bottom paint (will need a DA or other mechanical means) around the area you want to seal, then seal it. if you want to re-apply the bottom paint, apply over the 4200.

Got it thanks. That's what I'll do.

 

[JoLin]

Imagine a plastic tab with a couple screws that holds weight and force from your boat. Seems like an adhesive would serve a purpose to me.

It really isn't necessary. The fastening is mare than just a couple of screws. I've installed Smart Tabs on a 21' Pro-Line and a 16' Sylvan aluminum. Drill the holes the right size, seal them well and be done. No need to back butter them or seal the perimeters.

My .02

 

[Watermann]

It really isn't necessary. The fastening is mare than just a couple of screws. I've installed Smart Tabs on a 21' Pro-Line and a 16' Sylvan aluminum. Drill the holes the right size, seal them well and be done. No need to back butter them or seal the perimeters.

My .02

I used the 5200 as an adhesive as on my tab brackets and closed end blind rivets on the very bottom holes under the transom wood rather than screws. If the tabs were to ever suffer an impact I wager the 5200 back buttered bracket will offer more strength than a sealed screw hole where the screws are hanging onto only .100 AL or some FG.

My .02 is to add the 5200/4200 as an adhesive.

Oh hey further I forgot to mention I would suggest you find a different way to attach your transom tie downs so they don't rub on the tabs.

 

[frantically relaxing]

Another reason to 'back butter' the whole plate: shock and vibration absorption...

 

[StingrayMike]

X2
you have to remove the bottom paint.
the 4200/5200 sticks to the paint that is made to come off.QUOTE=Scott Danforth;n10297380]that is an ablative bottom paint. the 4200 stuck to the layer of paint that sloughed off. the 4200 didnt fail, it stuck to the paint, the paint did what the paint does and sloughed off taking the 4200 with it.

remove the bottom paint (will need a DA or other mechanical means) around the area you want to seal, then seal it. if you want to re-apply the bottom paint, apply over the 4200.[/QUOTE]

 

[crazy charlie]

I have used 5200 for many repairs/installs and have read all surfaces that it is used for.I dont ever remember reading where it adheres to bottom paint.when it states "clean surfaces" that would pertain to removing any bottom paint .Charlie