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finishing firewall
Posted: Thu Jan 07, 2021 10:47 am
by DonH
Purchase 3/4" oak finished on both sides plywood to make firewall for my speedster build. Think I would stain with cherry and then a good coat of varnish. Does that sound appropriate? If not please give me some advise. Thank you, Don Hanson
Re: finishing firewall
Posted: Thu Jan 07, 2021 11:54 am
by Mark Gregush
It's a speedster, you can color it any way you like.

Fine by me.
Re: finishing firewall
Posted: Thu Jan 07, 2021 12:03 pm
by TRDxB2
Stain to go with the rest of the Speedsters colors. What colors?
Test your stain choice on a piece of scrap before you stain the firewall. The wood used for the display or brochure isn't your wood.
Re: finishing firewall
Posted: Thu Jan 07, 2021 2:04 pm
by Mark Gregush
Also, read up on staining oak/plywood. There may be some steps that need done before applying the stain so it does not get splotchy.
Re: finishing firewall
Posted: Thu Jan 07, 2021 2:26 pm
by Quickm007
Hi Don, here bellow my original stock 1914 speedster project as well. It may inspire you.
Re: finishing firewall
Posted: Thu Jan 07, 2021 2:26 pm
by Steve Jelf
I would use paste wood filler on that oak before staining. And yes, try your finish on a scrap before you do the firewall. Cutting out a firewall should produce plenty of scrap for practice.
Re: finishing firewall
Posted: Thu Jan 07, 2021 5:24 pm
by DickC
I don't consider myself an expert as I learn something from every project. I have been a finish carpenter for 30+ years and have built furniture and made several "firewalls" for T's and one for a 1911 cadilac. In all cases I used furniture grade birch plywood. Furniture grade plywood has up to 9 layers depending on the thickness. Birch plywood will usually take stain evenly and have a very nice even grain. Also in each case the edge of the plywood was covered. On the early cars, the edge was covered with a brass trim piece and later cars the cowell fit over the plywood. Be sure to coat both sides with the same number of applications and today there are several products using epoxy which in mho is best.
Re: finishing firewall
Posted: Thu Jan 07, 2021 5:26 pm
by ivaldes1
Nice work. Does anyone have plans for a 1916 style that will have a brass square windshield?
Re: finishing firewall
Posted: Thu Jan 07, 2021 6:17 pm
by DonH
Thank you all for your input, it really is helpful and the photos fantastic help!!! Don
Re: finishing firewall
Posted: Thu Jan 07, 2021 6:28 pm
by Jack Putnam, in Ohio
If you are going to stain it with a cherry stain so that it will look like stained cherry, start with cherry veneer plywood. Oak will always look like an impostor. I use Minwax polyurethane finish which has UV protection. Let each coat dry for several days, block sand before the next coat. I usually use three or more coats of finish.
Re: finishing firewall
Posted: Thu Jan 07, 2021 9:48 pm
by JohnnyBuick
Don, These days you need to think out of the box !... Dont be a Lemming !!
I just stained my firewall few days ago in cedar on 1 side and on the otherside i went... gold baby !! Trust me the end result gets people crowding at the car shows , like bower birds they like shiney things ! Just Look at my last classy project

Re: finishing firewall
Posted: Fri Jan 08, 2021 9:24 am
by Quickm007
Johnny you did a fantastic job ! Congrats. How did you make the brass modling corner? I'm asking because I'm ready to install mine...
Re: finishing firewall
Posted: Fri Jan 08, 2021 10:29 am
by Original Smith
Be careful what you get. As I recall, what they call 3/4", is really not true! It is 23/32" That makes for a loose fit for the brass trim.
Re: finishing firewall
Posted: Fri Jan 08, 2021 10:38 am
by JohnnyBuick
The brass framing around the firewall comes in lengths with pre drilled holes from most vendors .
With the thinner wrap material you can tuck it around the edges of firewall & the brass frame fits , hides & holds it in place ..
With thicker wrap it wont fold over the edges & can bubble up & lift around edges there ..but you can cut your wrap material to the firewall edges with a ultra sharp new box cutter knife .
Just be sure your surface is smooth as !! ..with no pimples etc before you wrap..
I stained & laquered to perfection both sides of the firewall so if any deterioration was to occur i can simply remove the wrap.
You can actually buy wrap in all colors of chrome these days & or other many textures ...also wrap that has different woodgrain textures too so you wont have to stain or laquer your firewalls... just wrap your firewall in your favourite wood grain texture..

its cheaper and more effective & with minimal labour too...
Re: finishing firewall
Posted: Fri Jan 08, 2021 10:45 am
by JohnnyBuick
Heres one or 2 examples...
Re: finishing firewall
Posted: Sat Jan 09, 2021 11:49 am
by Ray Syverson
In my experience the oak plywood is easier to stain and finish than birch or cherry, which is more prone to showing blotchy areas when stained. So oak is a good pick. If I were you I would definitely do some testing on the scraps you have, following the directions for both the stain and the varnish. Make sure you let the stain dry thoroughly. Stain and varnish separately-don't use varnish-stain mix. Plug up any holes in the firewall before you varnish, so the varnish doesn't drip or seep down to the other surface.