How to Screw Into Fiberglass? (without cracking)

[Mr_Toad]

Hi, All,

I will sooninstall vinyl skirting all around my 2013 36FB...and would like advice on how to best screw the stainless steel screws into the outside surfaces. (Intended hardware is two 3/8 inch stainless steel screws to attach each of the DOT Common Sense Turn Fasteners, which mate with thematching DOT Common Sense canvas grommets).

I've read topics on some boating forums about screwing into fiberglass, for example:

1. PILOT HOLE & COUNTERSINK - Is it for sure best to first drill a pilot hole and then ALSO drill a slight countersink hole, to prevent cracking the fiberglass surface, and to prevent broken screws.
2. SEALANT FOR LUBE & LEAKS - After cleaning the drilled pilot hole with acetone, is it for sure best to inject a sealant into the pilot hole, before the screw....to help lube the screw as it enters and to prevent leaks in the future.
3. BEST SEALANT - Is 3M 5200 (or 4000) Marine Sealant the bestsealant to use (white or black)? Or could I use a clear silicone caulking kind of sealant?
4. WARRANTY IMPACT - Will I voidmy extended Redwood warranty by installing about a hundred turn fasteners on the sides of the 36FB?

Thank you in advance for your help!

Robt.



Edited by: Mr_Toad

[Elliott & Vicky]

Having worked on my boats for many years, and having worked with an experienced fibreglass boat builder to build a new cabin for my boat last winter, I'll offer my opinions.

1. Definitely drill a pilot hole before using the screws. As the glass you are drilling into is quite thin, drilling a countersink hole may weaken the glass. Be sure to tighten the screws by hand to keep from cracking the glass.

2./3. Definitely use a sealant. 5200 makes it almost impossible to remove items sealed in it without the use of strong solvents. 4200 is easier to remove. Turn fasteners do break over time so this should be a consideration. The choice of color is up to you. The sealant choice of color is up yo you. Same stuff, different color.

4. Call Redwood for the answer to this one.

[Happy Camper]

We put a skirt around the front of our 36RE using snaps. I was just at the facotry and nothing was said about voiding the warranty. In fact, they had to fix a crack in front of the bedroom slide without any charge to us.

[Mr_Toad]

Thank you, Elliot!

I do appreciate your detailed response. ...and have ordered some sealant off Amazon, and some 100CC syringes and short tips to see how they work as a more convenient way to deliver tinier quantities of sealant than the big tube.

Robt.

Edited by: Mr_Toad

[Elliott & Vicky]

Robert,.

I'm not sure if the syringes will work as the 4200 is pretty thick. Also, once opened, the tube has a short shelf life if it's not kept covered, and even then don't count on it being usable for more than a month.

Elliott

[Oregonbound]

I imagine you have or would think of this, but I would start with the most inconspicuous location until you feel confident in your technique.

p.s. I know you are not asking, but I've heard that some folks are bothered by the "ring of snaps" look around the RV when the skirting is taken off.

[Mr_Toad]

Thanks, Oregon,

That's a great idea, actually! (Hmm...the fender thingy over the wheels is broken on my FB, so maybe I should drill some practice holes there!)

Also, I do understand what you mean about the spiky look on the trailer sides....but the KOA I live in is only allowing skirting (versus constructing a foamboard perimeter, which would be superior insulation). There are a coupla Redwoods here that have the turn fasteners, and it's not so bad.)

After I finish this project, I'm going to make a summary post of this "DIY Skirting Project" ...just as an FYI. (For example, I think folks would benefit to learn that, despite the outrageous 3, 4, and 5+ dollar pricing on a single turn fastener/ grommet/ screwset (offered by the "canvas companies on Amazon and fleaBay"), that same set can be purchased for 92 cents from boating sites like SailRite.Com.

Anyway...

Robt.

[Mr_Toad]

Thanks, Elliot,

You make a good point...so I'm figuring, if the short tips placed on the 100cc syringe don't work, then I will simply drill a larger and larger "pilot" hole in the plastic tip of the syringe itself...until the goop will flow through.

My hope is to then have a more precise way to work the adhesive, and I can fill the disposable syringes as needed, then cover (with clear packing tape?) the larger adhesive to keep it fresh...at least for the two days I hope to finish this project.

Also, I mentioned to the OregonBound post that I'm planning on preparing a summary post of this "DIY Skirting Project"...if folks could perhaps use the info. (Especially how to avoid the rip-off pricing for DOT Common Sense Turn Fasteners being offered by the "canvas companies"...three, four, five+ dollars for a single fastener/ screw/ grommet set...versus 92 cents on SailRite.Com).

So, now I'm trying to devise a "pilot hole tool"..where I cansecurely attacha turn fastener at the end of a some type of handle, to more conveniently use to mark pilot holes...versus having to repeatedly grip the tiny fastener in what may be soon be some cold temperatures. (My custom stitched canvas is not going to arrive for almost a month...unfortunately.)

Robt.



Edited by: Mr_Toad

[Elliott & Vicky]

Robert,

I use a baggie or a piece of saran wrap over the end over which I wrap around it with electrical tape to hold it in place. It's worked well for me. By the way, if it's cold out, try to keep the 4200 at room temperature or slightly above.

Elliott