DAC90 crack repair - UK Vintage Radio Repair and Restoration Discussion Forum

stevekendal · 11th May 2016, 10:59 pm

Just bought a nice working black DAC90, the smooth knob version. It was cheap because it has a neat crack on the top of the case. The crack is central and runs from front to back. Best way of repairing and reinforcing. Araldite or fibre matting on the inside?

newlite4 · 12th May 2016, 11:36 am

If it is a clean crack, I would start off by just dribbling superglue into the crack using capillary action. If it is felt necessary to reinforce, then either use fibre glass mat or I tend to use fibre glass veroboard fixed on with araldite.
Neil

stevekendal · 12th May 2016, 11:51 am

Thanks, Ill see how the superglue holds

stevekendal · 13th May 2016, 9:23 pm

Actually, its split right through, but clean.

Lloyd 1985 · 14th May 2016, 9:42 am

Superglue will hold it very well, I've been using it on Bakelite for years with no trouble. For just a crack superglue on its own will be fine without any strengthening. Make sure to use good quality superglue, not those little tubes that are 10 for a quid are probably not very good, I always use Loctite and have never ha any problems.

Regards,
Lloyd

mark pirate · 14th May 2016, 9:53 am

I would reinforce it with fibreglass repair paste, I used it to good effect on my Bush TV32 cabinet.
If the crack is above the dropper though, I don't think it would be a good idea due to the excessive heat!

Mark

stevekendal · 14th May 2016, 10:40 am

Just the paste, without tissue?

telstar · 14th May 2016, 1:34 pm

Hi Steve. I have used the aluminium that is used on car body repairs, cut in to strips that will suit the size of the repair and araldited in place on the inside of the cabinet to give it a bit of strength.
Cheers
Mike

mark pirate · 14th May 2016, 7:02 pm

Quote:

Just the paste, without tissue?

I used just the paste, it is impregnated with fibreglass strands.
If you look through the pictures in my thread you can see how I repaired my cabinet. https://www.vintage-radio.net/forum/...d.php?t=124007

Mark

stevekendal · 15th May 2016, 12:36 pm

Done it with Loctite gel. Seems strong enough, just need to make it as invisible as possible now.

Lloyd 1985 · 16th May 2016, 7:46 am

If you let it overspill onto the visible surface then all you need is to sand it flat with very fine wet and dry sandpaper, P600 would be as coarse as I'd go, once flat polish it with either Brasso, T-cut, or greygate paste polishing No.5. It should polish up nicely!

Usual precautions with sanding Bakelite apply, do it outside, and wear a mask, some say that some bakelites contain asbestos. Also leave the superglue for a few days before sanding to make sure it's fully hardened.

Regards,
Lloyd.

11th May 2016, 10:59 pm	#1
stevekendal Heptode Join Date: Mar 2004 Location: Kendal, Cumbria, UK. Posts: 625	DAC90 crack repair Just bought a nice working black DAC90, the smooth knob version. It was cheap because it has a neat crack on the top of the case. The crack is central and runs from front to back. Best way of repairing and reinforcing. Araldite or fibre matting on the inside? __________________ Knobs and tubes rule ok

12th May 2016, 11:36 am	#2
newlite4 Octode Join Date: Nov 2003 Location: Bath, Somerset, UK. Posts: 1,805	Re: DAC90 crack repair If it is a clean crack, I would start off by just dribbling superglue into the crack using capillary action. If it is felt necessary to reinforce, then either use fibre glass mat or I tend to use fibre glass veroboard fixed on with araldite. Neil __________________ preserving the recent past, for the distant future.

12th May 2016, 11:51 am	#3
stevekendal Heptode Join Date: Mar 2004 Location: Kendal, Cumbria, UK. Posts: 625	Re: DAC90 crack repair Thanks, Ill see how the superglue holds __________________ Knobs and tubes rule ok

13th May 2016, 9:23 pm	#4
stevekendal Heptode Join Date: Mar 2004 Location: Kendal, Cumbria, UK. Posts: 625	Re: DAC90 crack repair Actually, its split right through, but clean. __________________ Knobs and tubes rule ok

14th May 2016, 9:42 am	#5
Lloyd 1985 Nonode Join Date: Jun 2008 Location: Coningsby, Lincolnshire, UK. Posts: 2,820	Re: DAC90 crack repair Superglue will hold it very well, I've been using it on Bakelite for years with no trouble. For just a crack superglue on its own will be fine without any strengthening. Make sure to use good quality superglue, not those little tubes that are 10 for a quid are probably not very good, I always use Loctite and have never ha any problems. Regards, Lloyd

14th May 2016, 9:53 am	#6
mark pirate Dekatron Join Date: Mar 2008 Location: Worthing, West Sussex, UK Posts: 5,185	Re: DAC90 crack repair I would reinforce it with fibreglass repair paste, I used it to good effect on my Bush TV32 cabinet. If the crack is above the dropper though, I don't think it would be a good idea due to the excessive heat! Mark

14th May 2016, 10:40 am	#7
stevekendal Heptode Join Date: Mar 2004 Location: Kendal, Cumbria, UK. Posts: 625	Re: DAC90 crack repair Just the paste, without tissue? __________________ Knobs and tubes rule ok

14th May 2016, 1:34 pm	#8
telstar Octode Join Date: Dec 2003 Location: Leeds, West Yorkshire, UK. Posts: 1,592	Re: DAC90 crack repair Hi Steve. I have used the aluminium that is used on car body repairs, cut in to strips that will suit the size of the repair and araldited in place on the inside of the cabinet to give it a bit of strength. Cheers Mike

15th May 2016, 12:36 pm	#10
stevekendal Heptode Join Date: Mar 2004 Location: Kendal, Cumbria, UK. Posts: 625	Re: DAC90 crack repair Done it with Loctite gel. Seems strong enough, just need to make it as invisible as possible now. __________________ Knobs and tubes rule ok

16th May 2016, 7:46 am	#11
Lloyd 1985 Nonode Join Date: Jun 2008 Location: Coningsby, Lincolnshire, UK. Posts: 2,820	Re: DAC90 crack repair If you let it overspill onto the visible surface then all you need is to sand it flat with very fine wet and dry sandpaper, P600 would be as coarse as I'd go, once flat polish it with either Brasso, T-cut, or greygate paste polishing No.5. It should polish up nicely! Usual precautions with sanding Bakelite apply, do it outside, and wear a mask, some say that some bakelites contain asbestos. Also leave the superglue for a few days before sanding to make sure it's fully hardened. Regards, Lloyd.