Window disaster

[pugwash]

Have just renewed the cracked and splintered perspex in my doghouse windows and what a delight it is - l can actually see out.

Last weekend I wielded the varnish brush and in a perfect drying wind managed to do everything until the rising wind blasted thistledown off the fields. But this was not the disaster.

Just before sunset I went around the boat with window cleaner. They needed a bit more buffing up so I grabbed the J cloth.

This was the cloth i had used while varnishing and it was lightly impregnated with No 1 thinners. Result: murky marks that can't be rubbed off. There is no warning on the tin and I have used thinners in plastic mugs so it never occurred to me that there would be a problem with perspex (not that I thought about it at the time, it was just a handy cloth).

But a problem there is. The starboard side windows are ruined by swirly rub-marks impregnating the surface. Horrible.

Does anybody know a treatment? I wondered if perhaps T-cut or similar might be used or would this make the problem worse? Any thoughts?

Thanks.

 

[longjohnsilver]

Have just renewed the cracked and splintered perspex in my doghouse windows and what a delight it is - l can actually see out.

Last weekend I wielded the varnish brush and in a perfect drying wind managed to do everything until the rising wind blasted thistledown off the fields. But this was not the disaster.

Just before sunset I went around the boat with window cleaner. They needed a bit more buffing up so I grabbed the J cloth.

This was the cloth i had used while varnishing and it was lightly impregnated with No 1 thinners. Result: murky marks that can't be rubbed off. There is no warning on the tin and I have used thinners in plastic mugs so it never occurred to me that there would be a problem with perspex (not that I thought about it at the time, it was just a handy cloth).

But a problem there is. The starboard side windows are ruined by swirly rub-marks impregnating the surface. Horrible.

Does anybody know a treatment? I wondered if perhaps T-cut or similar might be used or would this make the problem worse? Any thoughts?

Thanks.

I had a similar problem when using acetone to clean silicone sealant off perspex. Had to use very fine wet and dry and then a rubbing compound to bring it back to as it was. A bit time consuming but not a difficult job.

 

[cliff]

"wet & dry" to remove the marks and smooth the surface - start with 240 or 320 grit and work up to 1200 grit - clean well between changing grits. Finally, Farcla G3 and a slow speed polisher with foam head and buff to a clear finish.

 

[aquaplane]

How much was it for the new perspex? Look on the first fit as practice.

 

[awol]

Not for the faint-hearted and should be practised on scrap bits first - application of heat by blow torch or heatgun; a cook's brulé torch is good. Get it right and you can restore the gloss if not the optical clarity - linger too long and you are definitely re-glazing.

 

[snowleopard]

Various treatments are available but the most straightforward is Acrylic Polish (google it). You'll need a lot of elbow grease but it will eventually do the job.

Others that have been suggested include 1200 wet/dry used wet with coal tar soap. T-cut and International gelcoat polish may also work.

 

[V1701]

Another one to try is Meguiar's Plast-RX, did a good job on cloudy plastic sprayhood windows for me. Possibly not abrasive enough to use on it's own but for the final stages?

 

[Sandyman]

Have just renewed the cracked and splintered perspex in my doghouse windows and what a delight it is - l can actually see out.

Last weekend I wielded the varnish brush and in a perfect drying wind managed to do everything until the rising wind blasted thistledown off the fields. But this was not the disaster.

Just before sunset I went around the boat with window cleaner. They needed a bit more buffing up so I grabbed the J cloth.

This was the cloth i had used while varnishing and it was lightly impregnated with No 1 thinners. Result: murky marks that can't be rubbed off. There is no warning on the tin and I have used thinners in plastic mugs so it never occurred to me that there would be a problem with perspex (not that I thought about it at the time, it was just a handy cloth).

But a problem there is. The starboard side windows are ruined by swirly rub-marks impregnating the surface. Horrible.

Does anybody know a treatment? I wondered if perhaps T-cut or similar might be used or would this make the problem worse? Any thoughts?

Thanks.

What is a ''doghouse'' ??

 

[nickd]

Tooth paste should do the trick

 

[lenseman]

Toothpaste very good, as are some of the other 'polish' suggestions BUT 240 or 320 Grit Wet & Dry is far, far too course! 1200 Grit is the absolute maximum coarse Wet & Dry paper I would try suitably 'chalked'. Better to go 1600 or Crocus Paper and then rub "Oh So Gently" if going down this route!

CROCUS PAPER HERE:

http://www.m-p.co.uk/muk/parts/chap10/0482000115.htm

Always try a very small area on a side window first.

 

[snowleopard]

What is a ''doghouse'' ??

This is a doghouse...

 

[MissIsle]

The best & most thorough way is to go through the grades with wet n' dry. start at 600 & go down, 800, 1200, 2000, use washing up liquid as a lube for an even finer surface finish. Then T-Cut & finally polish with a fine automotive polish or jewlers rouge. I would work by hand as acrylic melts at arround 65ºC & a polishing mop can reach that.

There is a quicker fix if it's not the main screen. de-grease the screen with soapy water & dry. Then spray it with a clear air drying "ACRYLIC" lacquer. If you are any good with a spraycan it will be clear & see through, & you won't tell the difference unless you get right up to it. But make sure it's acrylic lacquer. You can even get tinted lacquers if you want.

 

[Ehecatl]

Perspex windows

Use toothpaste

 

[savageseadog]

I thought this thread was going to be about Bill Gates' carp software

 

[AntarcticPilot]

I thought this was going to be about Bill Gates!

 

[lenseman]

I thought this was going to be about Bill Gates!

ps: Are you on JCR SB at 4°N 25°W?

 

[AntarcticPilot]

ps: Are you on JCR SB at 4°N 25°W?

No, 'fraid not! I'm in Cambridge - but not much longer as I retire shortly.

 

[lenseman]

. . . . Does anybody know a treatment? . . . .

Whilst looking for something else, I found this company on e-Bay:

CARAVAN and BOAT WINDOWS
http://www.ebay.co.uk/itm/Plastic-W...ervan_Caravan_Accessories&hash=item1c04be711b

AIRCRAFT WINDOWS
http://www.ebay.co.uk/itm/Aircraft-...619?pt=UK_CPV_Aviation_SM&hash=item1c04be5093

I hope this helps?

 

[pugwash]

Thanks for all those neat suggestions. I had no idea it would be so easy. Elsewhere I found a suggestion for Brasso which might work. I'll get busy at the weekend, knees on the deck, bum in the air. Soft softly at first…

 

[cliff]

Toothpaste very good, as are some of the other 'polish' suggestions BUT 240 or 320 Grit Wet & Dry is far, far too course! 1200 Grit is the absolute maximum coarse Wet & Dry paper I would try suitably 'chalked'. Better to go 1600 or Crocus Paper and then rub "Oh So Gently" if going down this route!

I recommended starting with 240/320 grit to remove any surface irrugularities quickly then finer and finer poliching with finer grits up to 1200 grit - no need to go any finer - final polishing with a suitable polishing compound. Having done a number of "perspex" windows which were either solvent damaged or just scored the 240/320 grit made the initial resurfacing so much easier and quicker.