Can you put an Oil based Polyurethane over a water based ure

Anything to do with mechanical, construction etc

Can you put an Oil based Polyurethane over a water based ure

Postby lacofdfireman » Thu Mar 14, 2019 10:10 am

So the screw up keep happening. I kept reading about “The Mix” and people using MinnWax Spar as one of the ingredients. I figured great I already have some MinnWax spare urethane so must be the same. Well I was busy cutting boards and told my son to dilute the mixture 25% MinnWax and 75% Mineral spirits so he did. Then he started painting the trailer. Did a good portion of it then had to leave. I finished cutting boards and getting them installed and noticed he had maybe a cup leftover and that the two substances didn’t mix well together. The MinnWax sank and the Mineral spirts floated. Well stupid me decided just to finish off the 2 boards i had left which was about perfect. Then i was reading and realized the MinnWax I used was a water base. So that’s why they weren’t compatible.

So I woke up this morning figuring the trailer would be dry but it’s still a little wet. Not tacky or anything like that just seems a little moist. It was 35 degrees last night though.

So do I pull all my boards off and start over once again or can I do the correct “The Mix” over the top of this? Or should I just not bother with “The Mix” since I’m doing PMF exterior coating anyways?

This is what I tried to mix with the Mineral spirts.

Image

So basically what I’m asking is do I strip the trailer once more and start over again or can I just do PMF over this or even “The Mix” over this? Thanks.

Sent from my iPhone using Tapatalk Pro
lacofdfireman
Teardrop Master
 
Posts: 134
Joined: Thu Mar 17, 2016 5:59 pm

Re: Can you put an Oil based Polyurethane over a water based

Postby working on it » Thu Mar 14, 2019 10:59 am

lacofdfireman wrote:...So basically what I’m asking is do I strip the trailer once more and start over again or can I just do PMF over this or even “The Mix” over this? Thanks....

At this point, I wouldn't try using anything short of this:
klean strip.JPG
klean strip.JPG (57.87 KiB) Viewed 239 times
premium stripper product description.JPG
premium stripper product description.JPG (49.21 KiB) Viewed 239 times

It'll remove the poly already applied, and should make the wood ready for the correct oil-based "mix" . At least, it has worked for me on other oil-based paints, and should easily remove any water-based stuff. I prefer using the aircraft paint remover on car projects, so I tried this one on wood, instead. It was many years ago, and I don't remember what it did exactly, but Klean-Strip products are what I use.
2013 HHRv "squareback/squaredrop", semi-offroad, 4x8 TTT, 2065 lbs
  • *3500 lb Dexter EZ-Lube axle, w/brakes, 3000 lb. springs, & active-progressive bumpstops
  • *27x8.5-14LT all-terrain tires (x 3) *modified Weight Distribution system for single-beam tongue
  • *LED lighting, triple fans, Pioneer stereo *A/C & 110vac heat, Optima AGM, inverter & charger(s)
  • *extended-run, on-board, 2500w generator *Coleman dual-fuel stove & lantern, Ikea grill
  • *zinc/stainless steel front racks *98"L x 6"Dia. rooftop fishing rod/reel carrier
156212148599156215
User avatar
working on it
1000 Club
1000 Club
 
Posts: 1827
Images: 455
Joined: Tue Oct 04, 2011 9:05 pm
Location: DFW Texas

Re: Can you put an Oil based Polyurethane over a water based

Postby lacofdfireman » Thu Mar 14, 2019 11:36 am

Well I figure at this point I’m only into this reskin about $120(4 sheets Douglas Fir AC plywood) so I may just pull it off and reskin with 1/4” Baltic Birch that I found at Home Depot for $27 per sheet. Its cheaper than the Douglas Fir.

I I go the stripper route and it doesn’t work then I’m out that $40 at least. So might as well of just started over again. And I’m not sure how to use the stripper. Do you just roll it on? Then what does it do?

I have a few days to decide my game plan as I’m in the middle of moving also so time is short right now. Maybe after a few days what I’ve already done will be dry and I can do a test spot and see what happens. If the titebond 2 will adhere to this stuff I’ve already done I may just leave it where it’s at and do the PMF over this. Seems from talking and reading that when you do PMF “The Mix” really isn’t necessary.


Sent from my iPhone using Tapatalk Pro
lacofdfireman
Teardrop Master
 
Posts: 134
Joined: Thu Mar 17, 2016 5:59 pm
Top

Re: Can you put an Oil based Polyurethane over a water based

Postby Woodbutcher » Thu Mar 14, 2019 2:49 pm

If I was you, I would wait several days and see if your mixture dries hard. Since most of it was mineral spirits, that just evaporates with out leaving any build up. If you feel the wood, I would bet it doesn't feel much different then when you started. If it dries well, I would sand the wood real well with 80 Grit paper and do a small place with the Oil Based Spar Varathane or Poly, whichever you want. If it dries well you are good to go. If not, go to plan B. This is the easiest way I can see to move forward. You are no further behind if you chose to re skin.
User avatar
Woodbutcher
Platinum Donating Member
 
Posts: 4038
Images: 45
Joined: Fri Mar 10, 2006 10:01 pm
Location: Chicago Suburbs
Top

Can you put an Oil based Polyurethane over a water based ure

Postby lacofdfireman » Thu Mar 14, 2019 3:00 pm

Well had about 30minutes between loads moving so I got 3 of us on some tools and removed the outer skin once again in about 15minutes. So now off to Home Depot to buy 7 sheets of 1/4” Baltic birch to reskin yet one more time. I’ll feel better about it knowing the surfaces will he clean before doing the titebond 2 PMF method.

Image


Sent from my iPhone using Tapatalk Pro
lacofdfireman
Teardrop Master
 
Posts: 134
Joined: Thu Mar 17, 2016 5:59 pm
Top

Re: Can you put an Oil based Polyurethane over a water based

Postby Tomterrific » Fri Mar 15, 2019 6:15 am

I actually have some experience with this as a similar screw-up. I bought a cheap Harbor Freight sprayer for my deck railing. I was using Olympic oil stain. I was unfamiliar with the sprayer so I thought I should thin the stain. Oil uses solvent, right? Turns out the small amount of solvent I started with took forever to mix in with the stain, but it finally did. That's when I decided to read the label, water clean up. Tried a little bit of water and it mixed right in. The oil is homogenized into the water, like milk. Your screw-up is fine if you just let it dry. Solvent base urethane varnish should soak into the edges just fine and that is where we need to worry about water. Paint the exterior with high bond primer and you are home free to stick canvass over everything.

Tt
Fun fact:
The derivative of the word canvass is cannabis. US farmers were required to grow hemp due ring wartime because hemp makes the best rope and canvass possible. In 1937 DuPont lobbied congress to make hemp illegal to promote their new Nylon rope.
Tomterrific
The 300 Club
 
Posts: 410
Images: 8
Joined: Thu Mar 26, 2015 3:18 pm
Location: Central Ohio
Top


Return to Teardrop Construction Tips & Techniques

Who is online

Users browsing this forum: No registered users and 1 guest