Priming the plywood

[wormraper]

I have a quick question before I start my first build of the THT standard (36,24,36)

I know not to deviate from the plans at all, but this wasn't mentioned so I thought I'd ask... is it ok to use primer on the wood on the inside kind of to "seal" the wood???

[Frederic Gelinas]

I do that. With black automotive primer.

[Bill Fitzmaurice]

is it ok to use primer on the wood on the inside kind of to "seal" the wood???

No, because it may interfere with the adhesive bond. And there's no benefit to sealing it anyway.

[wormraper]

is it ok to use primer on the wood on the inside kind of to "seal" the wood???

No, because it may interfere with the adhesive bond. And there's no benefit to sealing it anyway.

and that be what I needed to know.... another quickie if at all possible. I know the recommended adhesive is the PL premium stuff. I noticed that they had a new PL out at Loewes today... It was a premium + or something like that version of the Premium.... basically it labeled it as stronger and faster drying... any downsides to that or should I stick to the standard premium??? (sorry for seemingly dumb questions but I wanna make sure not to F it up and I'm a "learner" for most DIY/ Home repair type of situations)

[Bill Fitzmaurice]

That would be PL Premium Advanced. I haven't tried it yet.

[LelandCrooks]

Interesting. I don't have it available yet. But please report on how it works. The tech data and specs look like a winner. Much faster, although cure is still 24hrs.

[bzb]

My wife accidentally picked up a tube at Home Depot for me. I haven't opened it yet, but I imagine it's not all that different. I actually prefer a little longer open time.

[Harley]

My wife accidentally picked up a tube at Home Depot for me..

We have one word for that around here....

SABOTAGE!

[wormraper]

lol, that's why I never have my wife pick up anything like that anymore. I end up taking it back 90% of the time.

[ewetho]

Baronvonsteve used some on the inner/first panels of the David. Said it was like an extra hand as you place the boards together they just stick. The only concern we had was the only close direct comparison I could find on their documentation indicated it was possibly not as strong as PL Premium. So the David started with PL Premium Adv but most is regular.

[Steve Regier]

I have used the PL Premium Advanced on my David build. Here's the deal:

1. Much higher viscosity. It is thick like mortar. Squeezing ample amounts out of the caulking gun will be a workout.

2. The initial bond is fantastic. It is like having a bead of double-stick tape down. I found that the part would stand fast and stay vertical while I worked it into place. It was a big help in setting the first few critical panels.

3. It does NOT expand as much. It will span a gap up to 3/8" but I would not count on I expanding to fill such a gap. I would only use it on panels with a good fit.

4. It cures rock hard. PL Premium I noticed is still a bit pliable when cured and when it is cut open or scraped out it seems to have pockets in it. The Advanced is solid and hard. I got some on the access cover by mistake and had to take a bit of wood off to get the PL removed.

5. PL Premium has a higher cured PSI rating than the advanced. Although 3000psi is probably fine.

Conclusions: I will be using both in my builds unless informed otherwise. I will use the Advanced to set the first few panels were I could use the extra initial holding force. Then I will switch to the Premium for the rest of the build were I will need the extra flow of the adhesive and the extra expansion to fill any gaps.

[wormraper]

I have used the PL Premium Advanced on my David build. Here's the deal:

1. Much higher viscosity. It is thick like mortar. Squeezing ample amounts out of the caulking gun will be a workout.

2. The initial bond is fantastic. It is like having a bead of double-stick tape down. I found that the part would stand fast and stay vertical while I worked it into place. It was a big help in setting the first few critical panels.

3. It does NOT expand as much. It will span a gap up to 3/8" but I would not count on I expanding to fill such a gap. I would only use it on panels with a good fit.

4. It cures rock hard. PL Premium I noticed is still a bit pliable when cured and when it is cut open or scraped out it seems to have pockets in it. The Advanced is solid and hard. I got some on the access cover by mistake and had to take a bit of wood off to get the PL removed.

5. PL Premium has a higher cured PSI rating than the advanced. Although 3000psi is probably fine.

Conclusions: I will be using both in my builds unless informed otherwise. I will use the Advanced to set the first few panels were I could use the extra initial holding force. Then I will switch to the Premium for the rest of the build were I will need the extra flow of the adhesive and the extra expansion to fill any gaps.

ooo, that's a good idea. use for the first couple panels where it's imperitive to stay up straight and regular for the rest.

[Steve Regier]

Yeah, it seems to have worked quite well. I will reserve final judgement until I check for air leaks. I also had another project. It was building the top half of a barn door. The Advanced was great for that. I was able to assemble all the parts and float them into place. The Advanced held fast as I turned and moved the door on the bench while making sure all corners were square aligned correctly. I then used the brad nailer to hold the panels until cured. The result was the best door I have built to date

[WB]

Interesting. I don't have it available yet. But please report on how it works. The tech data and specs look like a winner. Much faster, although cure is still 24hrs.

I tried it last summer and much prefer the regular PL for cabinet building. I bought it to apply the foam with. It's very tacky and grabbed the foam well after squishing the foam into it. Operating the caulking gun is also good for building Popeye forearms.

[LelandCrooks]

Thanks for the reports. The rock hard bond does not thrill me much. It might be stronger, but IMHO one of PL's biggest benefits is the slight flexibility of the bond. In my testing it gives more before failing than about anything else I tried, with greater strength before failure. I think that's an advantage in a pro cab that's going to be flung about. A brittle strong bond just shatters, PL fails slowly.

The initial bonding grab would be very helpful with interior starting panels for sure. I currently use an expanding poly hot glue that is every bit PL's equal to tack panels in place, with pl on most of the joint. It's not cheap though, the gun is 100 bucks and the glue is 10 bucks a tube, and does NOT go very far.