undercoat/sealer

Discuss all things Model T related.
Forum rules
If you need help logging in, or have question about how something works, use the Support forum located here Support Forum
Complete set of Forum Rules Forum Rules

Topic author
spadpilot
Posts: 39
Joined: Mon Jan 14, 2019 12:43 pm
First Name: David
Last Name: Carnahan
Location: Northern California
MTFCA Number: 49550

undercoat/sealer

Post by spadpilot » Wed Jan 16, 2019 4:33 pm

I am preparing to bolt my Currier speedster body (basically a buck board) to the frame and have been wondering about the best method / product to seal the underside. Hoping that the collective wisdom of the Forum might be able to shed some light on this for me.

Best,
Dave
...some people are like Slinkies....they're generally useless but fun to watch when you push them down the stairs.


Scott_Conger
Posts: 1571
Joined: Sun Jan 06, 2019 11:18 am
First Name: Scott
Last Name: Conger
Location: Clark, WY
Board Member Since: 2005

Re: undercoat/sealer

Post by Scott_Conger » Wed Jan 16, 2019 4:55 pm

That question should be asked of the fellow who built your body. He will be able to advise you.
Scott Conger

Full Flow Float Valves - deliver fuel like Henry intended!


Topic author
spadpilot
Posts: 39
Joined: Mon Jan 14, 2019 12:43 pm
First Name: David
Last Name: Carnahan
Location: Northern California
MTFCA Number: 49550

Re: undercoat/sealer

Post by spadpilot » Wed Jan 16, 2019 7:07 pm

I would have asked him, but he is very difficult to contact. That's why I'm asking the Forum.
...some people are like Slinkies....they're generally useless but fun to watch when you push them down the stairs.


signsup
Posts: 58
Joined: Thu Jan 10, 2019 12:56 pm
First Name: Robert
Last Name: Brough
Location: Winston, GA
MTFCA Number: 31990
MTFCI Number: 31990
Board Member Since: 2015

Re: undercoat/sealer

Post by signsup » Wed Jan 16, 2019 8:12 pm

Is this a wooden body? You are not talking about rustproofing or treating the frame, just the underside of the body?
I have used spray bedliner material from the local auto parts store in military vehicles where it will not be seen like fuel tank sumps, inside tool storage areas, etc.
How it adhears to wood, you would need to investigate.

I have heard from another forum member about the flex seal products being good for something like this.
Why do we drive on parkways and park on driveways?

1915 Model T War Wagon
1927 Model T Depot Hack
1942 Ford GPW
1943 Chevy 1 1/2 ton truck
1945 Studebaker Weasel

User avatar

Mark Gregush
Posts: 1164
Joined: Sat Jan 05, 2019 1:57 pm
First Name: Mark
Last Name: Gregush
Location: Portland Or
Board Member Since: 1999

Re: undercoat/sealer

Post by Mark Gregush » Wed Jan 16, 2019 8:41 pm

How much wet is it going to see? Why not just use a good grade of exterior paint? Or what ever coating you are going to use on the top side. There are T's out there that never had a drop of paint on the original wood and are still good today. While some may just have a tarp over them, bet most are stored inside not just sitting out in the rain day after day.
I know the voices aren't real but damn they have some good ideas! :roll:

1921 Huckster
1925 Cut down pickup


Topic author
spadpilot
Posts: 39
Joined: Mon Jan 14, 2019 12:43 pm
First Name: David
Last Name: Carnahan
Location: Northern California
MTFCA Number: 49550

Re: undercoat/sealer

Post by spadpilot » Wed Jan 16, 2019 8:42 pm

Robert.....Thanks for the reply....had not thought of the bed liner angle. Will check into it.
Best,
Dave

BTW.....I owned a Weasel for years....it was the only way into my cabin at 7500' in the Sierra's. Amazing vehicle but keeping the treads intact was a headache.
...some people are like Slinkies....they're generally useless but fun to watch when you push them down the stairs.


Topic author
spadpilot
Posts: 39
Joined: Mon Jan 14, 2019 12:43 pm
First Name: David
Last Name: Carnahan
Location: Northern California
MTFCA Number: 49550

Re: undercoat/sealer

Post by spadpilot » Wed Jan 16, 2019 8:45 pm

Mark......well, what you say is true. It probably will never see inclement weather and a good exterior paint will probably be sufficient. Sometimes I can't see the forest for the trees! Thanks for your suggestion!

Cheers,
Dave
...some people are like Slinkies....they're generally useless but fun to watch when you push them down the stairs.


John bevardos
Posts: 50
Joined: Mon Jan 07, 2019 1:58 am
First Name: John
Last Name: bevardos
Location: Los Angeles

Re: undercoat/sealer

Post by John bevardos » Wed Jan 16, 2019 8:46 pm

Mark,
how does your huckster perform with the chevy head?


Henry K. Lee
Posts: 1308
Joined: Sun Jan 06, 2019 11:09 am
First Name: Henry
Last Name: Lee
Location: South Pittsburg, TN

Re: undercoat/sealer

Post by Henry K. Lee » Wed Jan 16, 2019 8:53 pm

On the underside of wood products especially on a vehicle it is recommended to use a fennel seed based primer and paint. This is more natural to wood vs petroleum based paints. Fennel seed is normally called alkyl paint but check the can as the majority will say what the base is. Using turpentine as a reducer is recommended over mineral spirits. I used a semi gloss on the underside. Just prime the upper side and light sand, then apply battleship lanoleum. Some may be found at a True Value Hardware Store.

Hope this Helps!

All the Best,

Hank in Tin-A-See


Henry K. Lee
Posts: 1308
Joined: Sun Jan 06, 2019 11:09 am
First Name: Henry
Last Name: Lee
Location: South Pittsburg, TN

Re: undercoat/sealer

Post by Henry K. Lee » Wed Jan 16, 2019 8:59 pm

Some use a boiled linseed oil which is made from fennel seed. I have used it as well with excellent results. Preheating and skimming the top prior to applying is recommended with two light coats. Let dry for 2 weeks prior to top coating. A well preserved body.

Again, Hope this Helps,

Hank

User avatar

Mark Gregush
Posts: 1164
Joined: Sat Jan 05, 2019 1:57 pm
First Name: Mark
Last Name: Gregush
Location: Portland Or
Board Member Since: 1999

Re: undercoat/sealer

Post by Mark Gregush » Wed Jan 16, 2019 9:15 pm

Re huckster..it goes down the road Ok. I need to rethink some things on it like carb, water pump and ignition. I am also thinking about moving the gas tank to behind the seat on brackets and getting rid of the fuel pump stuff. The VW PICT carb with opened main jet did ok, got to over 50 on the flat, but not real fast. I have an OS1 Stromberg side draft that I would like to use. This is my only roadable T so I want to keep the wow but make more simple.
Good points from Hank on the painting.
I know the voices aren't real but damn they have some good ideas! :roll:

1921 Huckster
1925 Cut down pickup


Scott_Conger
Posts: 1571
Joined: Sun Jan 06, 2019 11:18 am
First Name: Scott
Last Name: Conger
Location: Clark, WY
Board Member Since: 2005

Re: undercoat/sealer

Post by Scott_Conger » Wed Jan 16, 2019 9:42 pm

When I was done rewooding the runabout body, before the metal was installed for the final time, I made a wiping varnish from Oil Based Spar Varnish and turpentine. Mixture was 50/50. Two coats went on. I am very pleased with the result and would not hesitate to do it again. Mineral spirits can be used instead of Turpentine, but I like the aroma of Turpentine and I had some available, so I used that.

If you consider useing Boiled Linseed Oil as any part of preparation or finish, ensure that you are not in a humid area or will store the vehicle in a non-ventilated area following a throrough soaking. Boiled Linseed oil can promote/feed Mildew. I would not recommend it's use if you are in the deep south or Texas. It's good with shellac for a french polish, good for making glazing putty lay down and OK for wiping down metal woodworking tools (I've done all of these). I also treated a rebuilt sash window with it...not so good...that window always suffered from mildew growth that no other sash would do. I learned about Boiled Linseed Oil and mildew after the fact. This was when I lived in Florida.

FWIW
Scott Conger

Full Flow Float Valves - deliver fuel like Henry intended!

User avatar

TRDxB2
Posts: 343
Joined: Tue Jan 08, 2019 4:56 pm
First Name: Frank
Last Name: Brandi
Location: Moline IL
Board Member Since: 2018

Re: undercoat/sealer

Post by TRDxB2 » Wed Jan 16, 2019 9:47 pm

Every car that I have owned that had undercoating rusted out worse than if it had none. The cause was that chips, untreated crevasse,etc trapped moisture and created a black hole for rust to start. Undercoating was also intended to deaden road noise."Ziebart" was a popular method in the 60's -80's. Its claim to fame was that is was self-sealing - so where are they now?. If you got a neck in their undercoating from a rock or something it was designed to seal over. Unfortunately the self-sealing fluid eventually sealed drain holes in rocker panels, door bottoms, and cross members. I had considered using bed liner recently but my undercoating memories caused a change of mind. I'm not sure what parts of the vehicle your trying to protect and from what. I expect that its going to be garaged as well
NOTE: The usual cause of rust-out fenders is dirt/mud that got trapped in some cranny, fender lip, that gets wet over and over even by washing the car. What ever you choose to put on just make sure there is a way to get it off later.


DHort
Posts: 485
Joined: Sun Jan 06, 2019 1:30 pm
First Name: DAVID
Last Name: HJORTNAES
Location: Men Falls, WI
MTFCA Number: 28762
MTFCI Number: 22402

Re: undercoat/sealer

Post by DHort » Wed Jan 16, 2019 11:32 pm

If you want it to stay clear use a sealer and than spar urethane, not polyurethane. If you want it painted you use a primer and than exterior latex. Some automotive primers and paints will work on wood. Check with the auto paint store.

User avatar

Mark Gregush
Posts: 1164
Joined: Sat Jan 05, 2019 1:57 pm
First Name: Mark
Last Name: Gregush
Location: Portland Or
Board Member Since: 1999

Re: undercoat/sealer

Post by Mark Gregush » Thu Jan 17, 2019 1:51 am

I had an infestation of roof rats, I had coated the wood box on my 25 cut down with Boiled Linseed Oil, the rats loved it. Maybe it killed them :twisted: or the cats did their job :lol:
I know the voices aren't real but damn they have some good ideas! :roll:

1921 Huckster
1925 Cut down pickup


jab35
Posts: 89
Joined: Sun Jan 06, 2019 12:28 pm
First Name: James
Last Name: Bartsch
Location: Dryden, NY 13053
MTFCA Number: 30615

Re: undercoat/sealer

Post by jab35 » Thu Jan 17, 2019 10:17 am

FWIW, Linseed oil comes from Flax seed, jb


signsup
Posts: 58
Joined: Thu Jan 10, 2019 12:56 pm
First Name: Robert
Last Name: Brough
Location: Winston, GA
MTFCA Number: 31990
MTFCI Number: 31990
Board Member Since: 2015

Re: undercoat/sealer

Post by signsup » Thu Jan 17, 2019 4:22 pm

Just watched a TV show, (so it must be real) and they used a a two part epoxy paint like a garage floor or porch paint for the underside of a wooden bed pick up. Owner lived on gravel road and they were concerened about debris coming up from the road on the bottom where you would not be able to rinse it off or inspect it much.

On my depot hack, I'm going to use the bedliner material on the wooden hood former oon the side under the hood so it can be wiped off and hide some oil and dirt. But I'll probably just use the same spar farnish on the bottom of the body that I'm using every where else on it.

Dit of s tink in the press lately about the Rhinoshield type paints for exterior of homes. Same as the Ziebart thing. It creats a seal. But, if there is any rot or moisture under the paint before it is applied, it has no way to get out, so the barrier breaks down and it does not adhere. Lifetime warranty claims are also not what they appear to be.
Why do we drive on parkways and park on driveways?

1915 Model T War Wagon
1927 Model T Depot Hack
1942 Ford GPW
1943 Chevy 1 1/2 ton truck
1945 Studebaker Weasel


Scott_Conger
Posts: 1571
Joined: Sun Jan 06, 2019 11:18 am
First Name: Scott
Last Name: Conger
Location: Clark, WY
Board Member Since: 2005

Re: undercoat/sealer

Post by Scott_Conger » Thu Jan 17, 2019 4:44 pm

Spar varnish out of the can as sold, will eventually fail, and when it does, the small areas which do, will peel. If you will thin it and use it as a wiping varnish, it will absorb somewhat into the grain, locking it on far better, and providing a better moisture barrier to boot.
Scott Conger

Full Flow Float Valves - deliver fuel like Henry intended!

User avatar

TRDxB2
Posts: 343
Joined: Tue Jan 08, 2019 4:56 pm
First Name: Frank
Last Name: Brandi
Location: Moline IL
Board Member Since: 2018

Re: undercoat/sealer

Post by TRDxB2 » Thu Jan 17, 2019 6:40 pm

I have used MINWAX Wood Hardner on spokes and other wood surfaces. There are similar products on the market too. Its consistency is so thin that l doubt if it could be applied upside down. The add says deep into the wood, I'd say 1/4" and it gives the wood a rich tone. I apply it generously and capture the run off, let it dry, sand, apply a another coat and sand again. The coating before sanding feels plastic like, after sanding its feels and looks varnished. Try it you'll like it. May be great for coil box wood too.
Attachments
Minwax.jpg
Minwax.jpg (12.37 KiB) Viewed 1146 times


Topic author
spadpilot
Posts: 39
Joined: Mon Jan 14, 2019 12:43 pm
First Name: David
Last Name: Carnahan
Location: Northern California
MTFCA Number: 49550

Re: undercoat/sealer

Post by spadpilot » Sat Jan 19, 2019 12:56 am

Many Thanks to all who responded.......I think I have some direction now!

Best,
Dave
...some people are like Slinkies....they're generally useless but fun to watch when you push them down the stairs.


Raoul von S.
Posts: 178
Joined: Mon Jan 07, 2019 1:12 am
First Name: Raoul
Last Name: Vaughn
Location: Egypt, Wa.

Re: undercoat/sealer

Post by Raoul von S. » Sat Jan 19, 2019 1:38 am

Coatings are a large part of my business, with a heavy emphasis on restoration/
preservation/old look kind of work. I am assuming this body in question is wood.

Several suggestions above regarding penetrating oils are good for durability and
and water repulsion. You want the material absorbed into the wood, not a skin-
coat sealer that WILL fail and cause you all sorts of grief and work to UN-do all
the work, only to do it right the 2nd time. But all this is predicated upon an end
goal of water repulsion and a less "sexy" finish than say, a spar varnish.

If you want the bright and glossy look of wood grain under a coat of glass, the
penetrating oils angle is not going to deliver like a skin-coat clear "sealer". But
this route combines two incompatible materials when water is added. The swelling
of the wood when wetted, will break down the clear coat "sealer" and grey the
wood in those areas where cracking occurs. And don't think for a minute that all
these sales pitches of "sealing" are going to overcome the joint and body flexing
of a car being driven. It WILL fail, and the work to fix it is large.

If you choose to go the penetrating oil route, the above suggestions to stay away
from linseed oil in humid regions is a solid piece of advice. Even "boiled", it retains
enough organic material to mold. In more arid climes, it is ideal. For humid areas,
I would suggest straight oil stains, such as the Elite line of Olympic Stain. For all
penetrating oils, plan to apply multiple coats, thinning the earliest coats drastically,
(like 75%) for DEEP absorbtion/penetration, and working up to a mix of 25% thinner
on final coats. I often use mineral spirits, but terpentine is also good. If it were
my project, I would aim for 5 coats, only applying a fresh coat after the last fully
dried, with a quick knock-down sanding between each. The first few coats will be
dry where you started before you can finish, making these go pretty quick. As the
mix is thickened, it will take longer. Plan on a couple days.

Besides the massive advantage that an oil-soaked wood will not soak in water, as
opposed to a water-thirsty wood coated in an minimally flexible plastic skin, the
penetrating oil can be reapplied over itself ad infinitum. When it begins to look
"dry", just slosh on some more and let it soak in. Not an option with skin-coat
"sealers".
"Working today, for a seamless tomorrow"

Post Reply Previous topicNext topic