Full boat tail on a Matrix - Page 9 - Fuel Economy, Hypermiling, EcoModding News and Forum

Weather Spotter · 01-06-2011, 12:11 AM

Good idea, the tape residue is not fun. I bet silicone cauck would come off better.

KITT222 · 01-06-2011, 12:12 AM

Looks great! Nice work. I'd suggest weather stripping, and gaffer/gorilla tape. gaffer/gorilla tape is as strong as duct tape, but won't leave the residue. Its what I have over my roof rails.

Weather Spotter · 01-06-2011, 12:17 AM

Quote:

Originally Posted by alohaspirit

can you use foil or something (plastic was stated)
to the protect the car and then seal it with fiberglass/bondo

(my first thought was expanding foam but i believe that would be difficult)

also what about a horse or wheeled dolley that
the boattail could sit on to assist with install/removal
(1 person job)

That was thought of

I might also add some eye hooks to the inside bottoms 2x4s. The open the hatch, back into garage (or under a tree) and hoist off with a come along or ratchet.

Fiberglass is out ( I am sick of the smell) but the bondo ideas (#3 on my list) is a strong contender.

Weather Spotter · 01-06-2011, 12:19 AM

I have gaffer tape ( sound tech here) but it would be an odd color choice. Not that that is a big deal but it is an small issue.

endurance · 01-06-2011, 02:16 AM

I've been enjoying from the sidelines and commend your hard work and engenuity on this project. IMHO bondo and weather stripping (adhered to the boattail) are going to be the best answer. Bondo your gaps to the absolute minimum, the apply the weather stripping. It's still not going to be perfect, but should keep the snow out.

redneck · 01-06-2011, 07:13 AM

I wouldn't use bondo by itself along the edges as it chips easily and can break off. Fiberglass resin would be better, then foam weather striping and possibly spray foam on the inside to make it form fitting. I don't think you can make it totally leak free.

As far as making it easy to put on and off try this.

Take a roll around floor jack and remove the steel pad that you lift with . There will be a hole where the pad was. Weld a similar size pin to your hitch. Place hitch pin in the hole, lift to put on or off. Use the pressure of the jack to help align top hole bolts.

It should be a one man operation.

>

Weather Spotter · 01-06-2011, 01:06 PM

Good ideas! keep them coming

@ redneck
how prone is bondo to chipping? I was thinking I might add fiberglass on top of it (I need a base to mold the fiberglass to).

The floor jack and pin idea is good for getting the hitch in, but the top brackets need the back pushed up and in as the tail wants to sag away from the top edge of the car.

To all, I want a water tight seal if I can get it. If I bondo then weather strip should this keep the water out? If not what do I need to do to protect the tail from rotting, warping etc?

endurance · 01-06-2011, 01:43 PM

Bondo is best kept to under 1/8" thick, as the thicker you make it, the more it tends to crack with age due to differential heating and shrinking compared to the material under it. However, for a year or two, it does just fine up to about a 1/4" in my experience.

Expansive foam can be hard to control, as it tends to grow for an hour after you spray it in. It's also sensitive to UV light and tends to degrade if not protected and I'm not sure how it will stand up to spray paint (does fine with household paint and it seems to protect it).

As for weather stripping, go to several stores and look at options. There is magnetic stuff (used on some steel doors and also used for sealing refrigerators) but it doesn't conform to curves very well. There are also different density foams. Most are not designed to stop water; they're designed to stop airflow. However, I suspect the more dense stuff will do both pretty well. You may want to go with two strips side by side if you can.

Cd · 01-06-2011, 02:17 PM

I second what everyone is saying about bondo. ( My first car had more bondo than sheetmetal. )

The stuff is very brittle - think of peanut brittle for instance. It's virtually identical to bondo ( in the amount of strength and brittleness that it has ), so probably not a good idea to use it around an area that will have constant stress placed on it.