poormans fiberglass overfoam prime or no

[Outoforder]

when poormans fiberglassing over foam, do you prime the foam?

Is it
foam, primer, glue, canvas?

or foam, glue, canvas?

[ghcoe]

That is the way I do it. I have done it both ways and I believe priming and then TBII works better.

[John61CT]

When the time comes I'm hoping the adhesive and primer are one and the same

as with Glidden Gripper.

Either way, I would prefer to not use a glue that isn't inherently water resistant if not proof.

The outer paint IMO is just to get a nice color and of course UV protection, not depending on that alone for sealing

[GPW]

“ Either way, I would prefer to not use a glue that isn't inherently water resistant if not proof. “ …
JMHO, we’ve pretty much given up on TB2 for the covering , only because of the eventual problems we had with the FoamStream and the High Humidity here … Gripper seems to be the new glue/primer of our choice … Proven Waterproof over time !!! ( Tested )

Just to mention , the thinned Gripper for the “ sizing coat “ is still very important … Highly thinned Gripper is not much for primer or glue , but really still serves to encapsulate each canvas fiber … ( tested ) And that also works well for Priming the foam …

[John61CT]

Problem is, Gripper isn't Gripper anymore

or at least we're starting over, the new formulation needs lots of real-life testing

[GPW]

OK, Let’s find a new “gripper” … Something HAS to work !!! Let the Testing begin ...

[ghcoe]

OK, Let’s find a new “gripper” … Something HAS to work !!! Let the Testing begin ...

I think we had a whole thread on that and it was inconclusive to what worked.

The problem is too many people trying to find something that works. Everyone wants their product to work so it makes it hard to tell what really is good and not good. Gripper had been on the market for years so it made a name for itself on it's own. The problem now, it seems, is that new products are old in just a few years and are replaced with something new again. This does not allow a product to stay on the market long enough to make a name for itself. I think this is planned to be honest, whether it is just marketing or because EPA makes you change something, maybe both I don't know.

TBII works and it works every time until there is no more TBII to be found. Just like Gripper. Sure we found it had a short coming, but that was fixed with a drip edge which, to be honest, should be used even without the use of TBII. Not only to protect the TBII from water saturation, but also protect the underside of the trailer. Remember it was you who mentioned your friend with the violins during a flood.

With that said I have used Valspar SeasonFlex. It was a miss tint that I picked up for $9.00 at Lowes. This was for another project. Usually on this project I paint 2"x4"'s to protect them from weather and I find I have to apply 2-4 coats before I am satisfied with the results. I was in a bit of a hurry on this project so I figured I would only apply 2 coats no matter the outcome. Turned out just one coat was good enough. The paint covered very well and it is a primer/paint combo. I was very impressed with the results. It is a bit more pricy at about $30.00 a gallon, but still doable especially if it only takes a coat or two. Test may be in the future.

[tony.latham]

I think we had a whole thread on that and it was inconclusive to what worked.

I thought about mentioning PMF in my book* but in the end, I avoided the subject since I have no experience with it and it's in what could be called an experimental covering method since there isn't an agreement on materials. (And I question calling it a "poor" man's alternative to fiberglass.)

If you read the material data safety sheet on Glidden Gripper, you'll understand why it's no longer manufactured. The stuff was nasty. The term carcinogenic is mentioned along with serious fume issues:
https://images.homedepot-static.com/catalog/pdfImages/ab/ab0a96d4-5e52-4d64-bda3-a9b32b3caea8.pdf



Tony

* But granted, my book isn't about building foamies. Someone else needs to write that book.

[GPW]

Drip edges , yeah , that solved a LOT of problems … 

We’ll just have to find some other nasty stuff… it’s out there , just waiting … Until then I have almost three gallons of TB2 to use up …

[John61CT]

Here's the nasty stuff I intend to try one day:

http://tnttt.com/viewtopic.php?p=1251965#p1251965

yes not cheap.

Discuss over there if you want

[ghcoe]

I thought about mentioning PMF in my book* but in the end, I avoided the subject since I have no experience with it and it's in what could be called an experimental covering method since there isn't an agreement on materials. (And I question calling it a "poor" man's alternative to fiberglass.)

Not experimental. Been used on boat decks for hundreds of years. Canoes were/are built with canvas. Some early manufactured camp/travel trailers where coated with canvas over hardboard. The main difference is the media used to bond the canvas and fill it. A lot of the traditional products are no longer made. So everyone is in the same boat (pun intended) trying to find products on the marked that will work.

[tony.latham]

A lot of the traditional products are no longer made.

And thus my point. Folks are experimenting to find suitable products to make PMF work. How many years ago did you test adhesives for your PMF build?

Perhaps experimental is too harsh of a word. But I think that's what it is. Here's an experimental aircraft I built:



A superb airplane that flew great on a EA-81 Subaru engine. (and is still flying under different ownership)

I'm not using experimental as a derisive word.



Tony

[ghcoe]

A lot of the traditional products are no longer made.

And thus my point. Folks are experimenting to find suitable products to make PMF work. How many years ago did you test adhesives for your PMF build?

Perhaps experimental is too harsh of a word. But I think that's what it is. Here's an experimental aircraft I built:



A superb airplane that flew great on a EA-81 Subaru engine. (and is still flying under different ownership)

I'm not using experimental as a derisive word.



Tony

Oh and some early aircraft also use cotton skins. Forgot about that one.

Nice experimental. I helped my neighbor build two experimentals.
Really most products work, it's just how well do they work.
By time I got here TBII was the way to go, and I still use it. Seems others are off to find something better, but I don't think there is a need at this point. I did find Gripper to be a good primer, but really in my experiences I find most primers work for my needs, which is not gluing canvas to foam, but priming foam for TBII and canvas for paint. I do understand the confusion though and yes hard to set one in stone at this point.

[GPW]

NICE Plane !!!!

[John61CT]

most primers work for my needs, which is not gluing canvas to foam, but priming foam for TBII and canvas for paint.

Does that mean primer goes between the foam and TB2?