Waterproofing the older 'white' foam board

[Bob A]

I thought I remembered that the hot glue does not stick to the foam board after it has been coated with Water Based Minwax Polycrylic? If so, coating the parts BEFORE assembly is out of the question and I need to assemble the aircraft first. Is this correct?

Thanks,

Bob

 

[TexMechsRobot]

Not necessarily true. I know some have had this issue but I haven't. I coated all of my FT Spitfire pieces front and back before gluing and it's holding together just fine.

I think it depends on the glue. Test a few spare pieces out and see what you think.

 

[kdobson83]

I'm pretty sure your supposed to use Oil based minwaxe, not water based. Try water proofing a scrap peice of foam and then glue it. If it doesn't seem to stick right, just sand the area u need to glue. But this is the first I've heard of it.
But don't forget, I'm 99% sure you need Oil based minwaxe, not water based.
Good luck.

 

[TexMechsRobot]

I'm pretty sure your supposed to use Oil based minwaxe, not water based. But don't forget, I'm 99% sure you need Oil based minwaxe, not water based.

Yikes! I didn't catch that part! YES! Use the oil based minwax and not the water based. The water based minwax will cause the paper to delaminate as soon as you start applying it. Hot glue sticking will be the least of your worries.

 

[Bob A]

Thanks for the responses. That was an 'oopsy' on my part stating water based minwax, that is something I use on r/c boats, works well and I like it there. I'm glad you caught it as it will make it "stick" in my mind to buy the 'oil' based product, Thank You!

Bob

 

[Bob A]

I hate to ride a 'dead horse', but I stumbled across the "Tips" video "Minwax on Your Plane by FliteTest"; "**DISCLAIMER**
HOT GLUE WILL NOT STICK TO MINWAX!
BE SURE TO GLUE YOUR AIRPLANE TOGETHER BEFORE APPLYING MINWAX. (I added the underline and bold)

Protect your scratch built foam airplane from moisture! David and Josh share a quick tip using Minwax Polyurethane."

NOW (caps just for emphasis) are there that many hot glues out there to be worring about? I was thinking, from watching other FT Builds, there was only the one, slightly opaque, hot glue you're supposed to use due to the heating point and cooling/curing of it?

This is becoming a real stumbling block for me. I have a couple of kits I have bought but don't feel confident enough to start building either one of them, one is the Storch.

Bob

 

[FlyingMonkey]

Have you tried any other glues? I have used the white version of gorilla glue, but not with waterproofing.

Another tip for extending the life of the white foamboard...

 

[Bob A]

Looks like the white Gorilla Glue is a good alternative, using tape to control excess foaming and clamping or weighing down the parts to keep them from moving during construction/drying.

Other points I've read is to build the plane, THEN paint with minwax for waterproofing and painting preparation. I think I may be overthinking the whole process.

Bob

 

[TexMechsRobot]

I hate to ride a 'dead horse', but I stumbled across the "Tips" video "Minwax on Your Plane by FliteTest"; "**DISCLAIMER**
HOT GLUE WILL NOT STICK TO MINWAX!
BE SURE TO GLUE YOUR AIRPLANE TOGETHER BEFORE APPLYING MINWAX. (I added the underline and bold)

Protect your scratch built foam airplane from moisture! David and Josh share a quick tip using Minwax Polyurethane."

NOW (caps just for emphasis) are there that many hot glues out there to be worring about? I was thinking, from watching other FT Builds, there was only the one, slightly opaque, hot glue you're supposed to use due to the heating point and cooling/curing of it?

This is becoming a real stumbling block for me. I have a couple of kits I have bought but don't feel confident enough to start building either one of them, one is the Storch.

Bob

This isn't completely true. I have no issues gluing planes together after coating in oil-based minwax.