Decided to paint just the bases before Indy, because they are easy to remove with just 4 screws. Each base is three parts bolted together: Top cap, middle curvy section, and flat bottom footer section.
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Only had time for two coats of flat black so far. The forecast calls for cold weather (30's and 40's and possibly some snow too) in SE Wisconsin, so it looks like I may have to wait several days before sanding and spraying on the finishing coats.
Ken has graciously offered to 3D print some small "time alignment" wedges for my speakers. I therefore took the speakers completely apart, did some careful wedge prototype testing and measuring, and then sent Ken the plans. Here are a few pics of the prototype wedges, which will be replaced later on. Thanks again, Ken, this will make the finished project look much better.
This is the part of speaker building that I do not like. Bondo, sanding, bondo, sanding, bondo, sanding, etc., etc. After gluing three of the five cabinets together and block sanding them completely flat, I cut two 7mm deep shadow lines along the glue joints.
I cut several more shadow lines for visual interest and to make the painting job easier. Plan is to paint the baffles and back panels Satin Redwood (Rustoleum 7767) and the sides Gloss Black (Rustoleum 7779). Then buff out the gloss black to a satin finish. Shadow lines will make this much easier to accomplish.
The shadow line trick has been around for a very long time. Here is a pic of a 1940's Zenith radio that I am restoring. Shadow lines cover up the top to side glue line and create a nice, attractive joint. Big 3 inch radius roundovers look really cool and retro!
Shot the first coat of primer today. Perfect weather for HVLP spraying. Temp in my garage was 72F with very low RH (relative humidity) and no wind. Since the weather looks like it will be good again tomorrow, I plan to block sand all parts flat again with 220 grit tomorrow morning and then spray a 2nd coat of primer. But then I'll have to wait a week or so before the 3rd or 4th coats, because the RH is forecast to be very high for the rest of the week.
I now have two coats of primer on all parts and have moved on to the next finishing stage. After sanding all parts smooth again with 220 grit, I noticed that there were still quite a few small scratches, little dents, and very small holes all over the place. So, instead of trying to fill them with regular two-part bondo, I picked up a tube of Bondo Glazing & Spot Putty. I saw JR using this on his cabinets, so I thought I would give it a try. Seems like some good stuff. It is designed to be used on top of primer, and since it is not as dense as regular bondo, it sands very quickly to a flat surface without removing all the primer.
The key to seeing all the scratches, dents, and other flaws is good lighting. I was watching some youtube cabinet finishing videos and noticed that some pros use long (30 to 40" or so) paint inspection light bars that shine light at a 90 degree angle across the panels to expose all the defects.
@jr@mac said:
Very soon in this process you should ditch power sanders and block sand everything.
Excellent tip. Otherwise, I'll end up power sanding all the primer off and be back to bare wood. So , I've ditched all my power sanders and have gone to complete hand sanding operations. Using two different sized sanding blocks and then completing the process by hand with no sanding block at all. Just a folded half sheet of 220 grit to polish the surface flat.
does that bondo stuff smell or any other strange behaviour - seems cheap enough. This is for on top of primer to fill out pinholes or before primer for bigger voids, dents etc or both? does it alos work for chipped corner or need something else?
@ani_101 said:
does that bondo stuff smell or any other strange behaviour - seems cheap enough. This is for on top of primer to fill out pinholes or before primer for bigger voids, dents etc or both? does it alos work for chipped corner or need something else?
Yes, you should do this outside with garage door wide open. Also, I'm using a spray painting mask to the avoid the fumes. This is highly flammable stuff.
It will not work for a larger chipped corner. For that, you would probably need to use spackling, wood filler, or something designed for that. The glazing is only designed for very small defects.
@jr@mac said:
Id caution against hand sanding as it can leave finger grooves.
Good point. I'll will try to avoid hand sanding, except for the rounded corners and curved shapes. For that I will still need to use a very light hand sanding technique.
Sprayed the 3rd coat of primer today. Each coat involved setting up and spraying a total of 22 parts for the stereo pair. Good news is that the finish is starting to look really smooth. The Bondo glazing & spot putty really made a huge improvement. I still have a few minor defects here and there, but they are becoming very hard to find or see. My thinking is that, at some point, I have to stop and say, "this is good enough." And since I only have a small amount of primer left, I'm going to sand everything down with 220 again and begin shooting the base coats.
Thanks for the tips! Keeps me going down the right track. I haven't sanded the 3rd coat yet, so I'll pick up some 400 grit and use that instead. The reason that I was going to use 220 was because of some cabinet painting vids that I recently watched. One youtuber recommended 220 between primer and top coats. He argued that the top coats would not adhere properly to the primer if sanded with 320 or 400. He said the top coat needed the rough texture of 220 or it might flake off.
I don't know if it makes a difference as regards the top coat sticking to primer coat, but I'm NOT using automotive two part primer or automotice two part top coats. I'm using Rustoleum oil based primer, without hardener, which I thinned down with about 20% mineral spirits so that it would spray well with my cheapy HF purple spray gun (I have 1.4mm and 1.8mm tips). I'm using the 1.8mm tip. For the top coats, I will be using Rustoleum oil based enamels. I have a can of VanSickle clear hardener/catalyst that I could add to the enamel, but I do not plan to use it because I have never used a hardener/catalyst before and I am afraid that I might screw it up. I plan to simply thin the oil based enamels down with mineral spirits until I get a nice, even spray that flows out and levels to a nice, finished surface. I usually get a little bit of orange peel on the final coat, but I'm OK with that.
Most reactive finishes such as rustoleum have a "re-coat window". Check the can for recommended re-coat time. If you have to exceed that time then more coarse sanding can help with adhesion. With rustoleum oil based enamels the window is pretty big, it cures rather slowly without any catalyst or hardener added. I would try to plan my two or three finish coats to be within that time window for best adhesion.
Thanks Bob. Recoat time is listed on the can as 24 hours. I'll try to stay within that window and use light 400 grit sanding between coats. Maybe get one of those soft sponge type sanding pads that apply an even pressure to the paper.
Should be good.
I like cork, hard felt, rubber sanding pads for flat surface finish sanding. The foam backed pads work good for contours. I like to back them with something somewhat firm but flexible. Old sandpaper works good for that.
Comments
I'm guessing you could still get them from. Other vendors. You might even reach out to Techtonic and see if they can sell you a few.
I might have 2-4 if you want them send me a PM.
Always a bummer when a driver we like goes NLA.
Decided to paint just the bases before Indy, because they are easy to remove with just 4 screws. Each base is three parts bolted together: Top cap, middle curvy section, and flat bottom footer section.
,
Only had time for two coats of flat black so far. The forecast calls for cold weather (30's and 40's and possibly some snow too) in SE Wisconsin, so it looks like I may have to wait several days before sanding and spraying on the finishing coats.
Ken has graciously offered to 3D print some small "time alignment" wedges for my speakers. I therefore took the speakers completely apart, did some careful wedge prototype testing and measuring, and then sent Ken the plans. Here are a few pics of the prototype wedges, which will be replaced later on. Thanks again, Ken, this will make the finished project look much better.
This is the part of speaker building that I do not like. Bondo, sanding, bondo, sanding, bondo, sanding, etc., etc. After gluing three of the five cabinets together and block sanding them completely flat, I cut two 7mm deep shadow lines along the glue joints.
I cut several more shadow lines for visual interest and to make the painting job easier. Plan is to paint the baffles and back panels Satin Redwood (Rustoleum 7767) and the sides Gloss Black (Rustoleum 7779). Then buff out the gloss black to a satin finish. Shadow lines will make this much easier to accomplish.
The shadow line trick has been around for a very long time. Here is a pic of a 1940's Zenith radio that I am restoring. Shadow lines cover up the top to side glue line and create a nice, attractive joint. Big 3 inch radius roundovers look really cool and retro!
Shot the first coat of primer today. Perfect weather for HVLP spraying. Temp in my garage was 72F with very low RH (relative humidity) and no wind. Since the weather looks like it will be good again tomorrow, I plan to block sand all parts flat again with 220 grit tomorrow morning and then spray a 2nd coat of primer. But then I'll have to wait a week or so before the 3rd or 4th coats, because the RH is forecast to be very high for the rest of the week.
Bill, just sent you a message.
Thanks, Ken. Got it.
I now have two coats of primer on all parts and have moved on to the next finishing stage. After sanding all parts smooth again with 220 grit, I noticed that there were still quite a few small scratches, little dents, and very small holes all over the place. So, instead of trying to fill them with regular two-part bondo, I picked up a tube of Bondo Glazing & Spot Putty. I saw JR using this on his cabinets, so I thought I would give it a try. Seems like some good stuff. It is designed to be used on top of primer, and since it is not as dense as regular bondo, it sands very quickly to a flat surface without removing all the primer.
The key to seeing all the scratches, dents, and other flaws is good lighting. I was watching some youtube cabinet finishing videos and noticed that some pros use long (30 to 40" or so) paint inspection light bars that shine light at a 90 degree angle across the panels to expose all the defects.
Very soon in this process you should ditch power sanders and block sand everything.
what do you use for block sanding?
Excellent tip. Otherwise, I'll end up power sanding all the primer off and be back to bare wood. So , I've ditched all my power sanders and have gone to complete hand sanding operations. Using two different sized sanding blocks and then completing the process by hand with no sanding block at all. Just a folded half sheet of 220 grit to polish the surface flat.
Warner #436 Sanding Block (uses quarter sheets):
Longer block (uses half sheets):
Simple folded half sheet without block:
does that bondo stuff smell or any other strange behaviour - seems cheap enough. This is for on top of primer to fill out pinholes or before primer for bigger voids, dents etc or both? does it alos work for chipped corner or need something else?
Id caution against hand sanding as it can leave finger grooves.
Yes, you should do this outside with garage door wide open. Also, I'm using a spray painting mask to the avoid the fumes. This is highly flammable stuff.
It will not work for a larger chipped corner. For that, you would probably need to use spackling, wood filler, or something designed for that. The glazing is only designed for very small defects.
Good point. I'll will try to avoid hand sanding, except for the rounded corners and curved shapes. For that I will still need to use a very light hand sanding technique.
Sprayed the 3rd coat of primer today. Each coat involved setting up and spraying a total of 22 parts for the stereo pair. Good news is that the finish is starting to look really smooth. The Bondo glazing & spot putty really made a huge improvement. I still have a few minor defects here and there, but they are becoming very hard to find or see. My thinking is that, at some point, I have to stop and say, "this is good enough." And since I only have a small amount of primer left, I'm going to sand everything down with 220 again and begin shooting the base coats.
Bill, in my opinion 220 is too aggressive, I wood use 400 paper.
I agree with Nick.
Makes you appreciate the shit out of automotive painters.
Be diligent about cleaning between stages, as well.
Thanks for the tips! Keeps me going down the right track. I haven't sanded the 3rd coat yet, so I'll pick up some 400 grit and use that instead. The reason that I was going to use 220 was because of some cabinet painting vids that I recently watched. One youtuber recommended 220 between primer and top coats. He argued that the top coats would not adhere properly to the primer if sanded with 320 or 400. He said the top coat needed the rough texture of 220 or it might flake off.
I don't know if it makes a difference as regards the top coat sticking to primer coat, but I'm NOT using automotive two part primer or automotice two part top coats. I'm using Rustoleum oil based primer, without hardener, which I thinned down with about 20% mineral spirits so that it would spray well with my cheapy HF purple spray gun (I have 1.4mm and 1.8mm tips). I'm using the 1.8mm tip. For the top coats, I will be using Rustoleum oil based enamels. I have a can of VanSickle clear hardener/catalyst that I could add to the enamel, but I do not plan to use it because I have never used a hardener/catalyst before and I am afraid that I might screw it up. I plan to simply thin the oil based enamels down with mineral spirits until I get a nice, even spray that flows out and levels to a nice, finished surface. I usually get a little bit of orange peel on the final coat, but I'm OK with that.
Most reactive finishes such as rustoleum have a "re-coat window". Check the can for recommended re-coat time. If you have to exceed that time then more coarse sanding can help with adhesion. With rustoleum oil based enamels the window is pretty big, it cures rather slowly without any catalyst or hardener added. I would try to plan my two or three finish coats to be within that time window for best adhesion.
Thanks Bob. Recoat time is listed on the can as 24 hours. I'll try to stay within that window and use light 400 grit sanding between coats. Maybe get one of those soft sponge type sanding pads that apply an even pressure to the paper.
Should be good.
I like cork, hard felt, rubber sanding pads for flat surface finish sanding. The foam backed pads work good for contours. I like to back them with something somewhat firm but flexible. Old sandpaper works good for that.
Your work so far looks really good! Can't wait to see them completed.