Seam Rash advice
Printed From: The Brick-yard
Category: T3 Section
Forum Name: T3 Tech help
Forum Description: Forum for T3 specific problems.
URL: http://www.brick-yard.co.uk/forum/forum_posts.asp?TID=83418
Printed Date: 19 Apr 24 at 14:09
Software Version: Web Wiz Forums 12.06 - https://www.webwizforums.com
Topic: Seam Rash advice
Posted By: booted
Subject: Seam Rash advice
Date Posted: 17 Jan 14 at 14:51
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the bodgedmobile panel has a bit of seam rash but a fair bit of water getting through the knackered seam sealer. i have now taken out all ot the loft insulation that was starting to get wet, I have got myself a small spot blaster so plan to stat sorting them out but at what stage should the new seam sealer go in? the other stages as i see it are media blast /wire brush treat with vactan [ unless there is noew somthing better ] zinc primer normal primer paint seam sealer between the two different primers? somewhere else? or am i miles out? ta i have wire brushed it as much as i can inside since i took this its solid and just surface rust , not too bad on the outside just the old sealer cream crackered http://smg.photobucket.com/user/booted/media/Panel/20140102_120749_zpsgmoko71e.jpg.html" rel="nofollow">  |
Replies:
Posted By: Retro Restore
Date Posted: 18 Jan 14 at 19:47
Hi Booted, I teach vehicle body repair and paint at kirklees college, so I can give you plenty of free advice. First of all sand blast the required areas, do not use zink primer as that is genrally used between panels for resistance spot welding, you need to treat any bare metal with acid etch primer, the best type is applied with a spray gun. An alternative is upol acid 8 avalable in an aerosol, aply one coat of 1k primer over the etch primer, then if needed prepare the primmer with 400 sand paper, do not use any wet n dry because primer is a porous substrate, if you rub through to bare metal dust a bit of etch on, once you are happy with your preparation apply your seam sealer, allow it to cure as stated on the product data then apply your top coat, this can be an aerosol but it is better to use 2K products. Now you just need to appy a coat of wax oil. If you want any more advice I am more than happy to talk you through it over the phone  ------------- Latest Project 1982 T3 air cooled camper |
Posted By: booted
Date Posted: 18 Jan 14 at 20:25
| Thanks |
Posted By: max and caddy
Date Posted: 18 Jan 14 at 21:13
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Sounds about right...only one m in primer though teach...also this kinda weather is not good for any kind of bare metally painty kind of activity...unless your in a proper dry workshop environment...the upol 8 etch does seem very good a stopping rust, I painted a home made bike rack with made of 1" box steel and its sat outside ever since without rusting to any major degree...over 3 years now..but as above, in theory primer is porous. I personally use a vw product called 1k wash primer...and apply it with a brush and really squeeze it into the seam untill I see it exude from the other side...that way I know the full seam is full of paint and hopefully seal out moisture...it can take a while to dry doing this so don't rush it..I can dig out a part number for this product if you want it. After seam sealing and finish coats it's very worth spraying and then ideally brushing as well to fill gaps a wax like dynax S50 from bilt hamber into the rear of the seams...I also waft a hot air gum over the wax and marvel as it melts and runs into the seam...then sets..must be as good as it gets for butted and spotted flanges I reckon? |
Posted By: Retro Restore
Date Posted: 18 Jan 14 at 21:34
Primer, sorry I have been rushing round like an idiot today, never bothered to check my grammar  good point about the wax oil.------------- Latest Project 1982 T3 air cooled camper |
Posted By: max and caddy
Date Posted: 18 Jan 14 at 21:57
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No worrys...your grammar is fine..its the spelling..(only kidding...mines proper well crap) also upol acid etch 8 is available in a 1/2 litre brushing tin...expensive like but it is a very good, tough, primer....a DA will polish it rather than sand it as it sticks so well and sets so hard! Thing is with the T3 it actually impossible to remove the rust from the seams without parting the panels...fine if your swapping a panel for new either side but normally it's the B post or similar and rust can only be attacked from the outer surface...so I go with media blasting, sharp pointed scrapers and picks to dig out as much rust as possible, Stanley knife dragged down the gap to shift as much as possible and sometimes it's even possible to get the blade between the panels at some points...then "vactan" although I must say I think the stuff is over rated...used it once and wasn't impressed...best with phosphoric acid or kurust wiped off so it isn't thick and shiney and then flood the seam with some kind of etch primer. Seams to work! 
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Posted By: booted
Date Posted: 18 Jan 14 at 23:23
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Might be a silly question ....Is the wash primer a seam sealer or paint Can i put some sodt of sealer on the seams as a temp measure untill the weather is better tp try to keep the water out |
Posted By: max and caddy
Date Posted: 18 Jan 14 at 23:29
| Wash primer is basicly etch primer...it's thin..best thing you can do for your seams in the short term is to slap a brush load of cavity wax onto them...will be sticky and messy but will displace water and slow the rust down as much as is possible...waxoil itself is not a good brand...but better than nowt, be sure to remove every trace of it before future paint repairs etc however. |
Posted By: booted
Date Posted: 18 Jan 14 at 23:48
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Thanks . i have got some knocking about |
Posted By: DavidPallister
Date Posted: 19 Jan 14 at 10:03
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Little trick I've done that i find useful: Drill a small hole into the nozzle of the etch aerosol and put a WD40 type straw/tube into it, this then allows you to spray it right into the seams
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Posted By: booted
Date Posted: 23 Aug 14 at 10:21
What is the best media to use to blast the seams , i really need to get my finger out and get cracking with this ?? there is a machine mart opened up near me i was going to try this stuffClarke 20kg 60-80 Grit Aluminium Oxide Powderor something different, will the blastin leave a residue or some kind
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Posted By: BUBBLE MEISTER
Date Posted: 23 Aug 14 at 17:46
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Thanks guys, this is really informative. Im having my van restored now. Im about to spray my door handles. Do i need any special primer since they're not steel? Would an enamel finish be appropriate? ------------- I have BUBBLE the '85B 1.9DF (currently a DG!) WBX Camper. 29 Yrs Young. Tis Tracie's V Bubble U. |
Posted By: youthy giblets
Date Posted: 24 Aug 14 at 01:03
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Don't mean to piss on your bonfire but once that rust is between the seams its always going to be in there so unless you take the arches out there's a good chance its always going to come back to haunt you at some point. I believe most if the seam rot on these vans starts from inside out as there's no seam sealer on the inside and condensation etc builds up over the years and starts creeping into the seams. I have however in the past carefully removed seam sealer from the outside using a thin cutting disc in the grinder/dremel etc just don't go in to deep or you will start to cut into spot welds. I usually use plenty of 2k etch/wash primer. On one of my old vans I literally poured it into the inside of the van and let it run through the seams etc and removed excess from outside with a cloth soaked in thinners. Then re-sealed outer seams and lashings of waxoil inside the van. My logic was to try and stop oxiditisation anymore. If no oxygen can get back in there coz its full of paint and waxoil then surely it will help?? Worked for nearly 5 years using the van all year round before any of the seams showed signs of bubbling. Jakes Atlantic looked like that from inside so we pulled the arches off and fitted new. Catch 22 tho, all the rust etc removed but spurious arches aren't as good as originals. |
Posted By: Dr Dub
Date Posted: 02 Sep 14 at 22:28
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Totally agree - the rust is usually from inside so whatever you do is damage limitation. Media blasting followed by the correct coatings will keep it away for a few years. The problem is that blasting will only go as far into the seam as the size of the media allows so replacement is enevitible if you want it gone for good. Then use a good flexible seam sealer that doesn't crack. ------------- 2011 camperjam tug and chug team member CALLERS NEVER FAIL - DREAMERS USE E MAIL !! Bristol Area-Tel 07721577612 |
Posted By: booted
Date Posted: 03 Sep 14 at 15:56
| replacement is not an option other than the ns rear arch, all seams ar solid but there is some surface rust on the inside and rain gets in. so need to trat and re seal as well as possible |