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How to Spec Slide Liners, Dunnage, and Masking: What to Send H-O for a Quote
The wear-and-protection layer of a switchgear build is five different specs wearing one purchase order: slide liners, shipping dunnage, surface masking, the felt-and-foam support layer, and enclosure venting. Each zone has its own two or three numbers that make the quote come back right the first time, and none of them is exotic. This article is the checklist the H-O applications team works from, organized by zone the way the parent application page is: what to send for each part type, why it changes the answer, and what happens after you hit send.
The repeated theme: these parts are specified once and re-bought for years, so five minutes against the checklist breaks the cycle of inheriting somebody else's unexamined spec.
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What to send, zone by zone
| Part type | Send this | What it decides |
|---|---|---|
| Slide liners | Rail material and finish; contact-pressure estimate (mass over real contact area); stroke length; cycles per year | The family: UHMW wear tape for heavy point loads, skived PTFE film for effort-critical light slides, PTFE-coated fiberglass for abrasive surfaces. Peel per ASTM D3330 is checked against the rail finish. |
| Shipping dunnage | Supported masses and bearing areas per block; one-way or reusable; finished-surface contact points | The density: static stress in psi against each grade's ASTM D3575 compressive data. 1.9# EPE for broad light braces, 2.8# where the same area carries more, crosslinked PE (ClipFoam) for precision and reuse, EVA at contact-sensitive corners, Wonder Pads between stacked finished faces. |
| Masking film | The finish (powder coat, paint, brushed metal, glass); expected dwell; indoor or outdoor exposure | The tack class: standard-tack PolyMask 5180C/5188 on durable faces, 4040 low-tack (3 mil per its TDS) on delicate or freshly cured finishes, glass film on glazing. Peel per ASTM D3330 and film tensile per ASTM D882. |
| Felt, cork & PVC foam | The function (wiper, wick, spacer, anti-slip pad, low-load gasket); grade or density if known; for wicks, the oil | The grade: SAE felt F-1 to F-55 by density and firmness (ASTM D461 methods), cork for anti-slip and isolation, PVC foam for low-load gasketing, incl. the HT70 UL grade where a UL 94 HF-1 class is required. |
| Vents & intake filters | Enclosure rating context; the dust problem (or PPI if known); coating need; any flame-class requirement | The grade pair: ePTFE vent membrane for pressure equalization, reticulated PU foam 10 to 80 PPI for intakes, with UL94 HF-1 grades (uncoated and PVC-coated) where the rating requires and coated grades outdoors (UV per ASTM G154). |
Quantities, kits, and presentation
Two ordering details save the most rework. First, quantities for prototype and production, because the converting method follows them: flatbed die-cutting for volume parts, slitting for liner and masking widths, CNC waterjet for thick foam dunnage.
Second, presentation: liner strips kiss-cut on liner with squared, sealed ends; masking slit and die-cut to panel sizes so application is a lay-down, not a trimming exercise; and dunnage cut as complete kits to the packing drawing (EPE braces, ClipFoam cradles, EVA corners, Wonder Pad separation layers) so the lineup packs the same way every time.
Kitting and waterjet cutting are in-house capabilities, and reusable program dunnage ships with material traceability like any other part.
What happens after you send it
- Drawing review. Typically opened the same business day; the response is either a material direction per zone or the specific missing numbers.
- Material direction and quote. Family, grade, and converting plan per part, with values cited to the maker's TDS (D3575 compressive data for foams, D3330 peel for tapes and films, D461 for felts).
- Samples. Typically 3 to 5 business days for common die-cut configurations on materials we keep on hand; trial masking on a production-finish sample before committing a lineup.
- Production. Standard production runs about two weeks after drawing approval; special orders are quoted to the job. MOQ varies by material and part.
Documentation available on request: material technical data sheet, certificate of conformance, and lot traceability, under our ISO 9001:2015 certified quality management system. H-O is a die-cut converter, not a raw-material producer; we do not mold or extrude in-house, and molded or extruded profiles are coordinated through our partner network in Winsted, Connecticut.
The mistakes this checklist prevents
| Spec mistake | What it causes | Checklist line that catches it |
|---|---|---|
| Liner picked by "slipperiest" | Soft PTFE cold-flowing through under breaker point loads | Contact-pressure estimate |
| Dunnage density picked by feel | Soft blocks bottoming out; firm corners transmitting the hit into a door edge | Masses and bearing areas |
| Masking left on through a hot summer | Adhesive ghosting on a powder-coated door at removal | Dwell and exposure |
| Standard tack on a delicate finish | A marked brushed face that needed the low-tack grade | The finish callout |
| Filter PPI too fine for the dust load | A blinded intake starving the fans in a season | The dust problem, not just a PPI |
| Flame class discovered at inspection | Standard foam in an assembly that needed the UL94 HF-1 grade | Flame-class requirement line |
Frequently asked questions
How do I compute the static stress for dunnage foam?
Supported mass divided by the foam's actual bearing area, in psi, block by block. Then pick the density whose compressive data (per ASTM D3575 on the grade TDS) brackets that stress with cushion travel to spare: foam loaded past its range bottoms out and transmits the shock; foam loaded far below it never engages. The masses and footprints come straight off the packing layout; send them with the drawing and the sizing is arithmetic.
Can H-O cut complete dunnage kits, not just sheets?
Yes, that is the point. Send the packing drawing (or the gear drawing and shipping method) and H-O waterjet-cuts and die-cuts the full set: EPE braces and blocks, ClipFoam cradles, EVA corners, and Wonder Pad separation layers, kitted so the lineup packs the same way every time. Reusable program dunnage ships with material traceability like any other part.
Which protective film will not leave residue on a powder-coated door?
Matched correctly and removed inside its service window, any of them; the failures come from mismatch and overstay. Use standard-tack PolyMask on durable painted and powder-coated faces, the 4040 low-tack grade on delicate, textured, or freshly cured finishes, and glass film on glazing. Film adhesion builds with time and heat, so state the expected dwell and any outdoor exposure when ordering, and trial the film on a production-finish sample first.
When do I need the HF-1 flame-class filter foam?
Wherever the enclosure or room rating requires a flame class on the foam: fire-rated switchgear rooms and listed assemblies typically do. The reticulated line carries UL94 HF-1 grades in both uncoated and PVC-coated forms, with the class cited on those TDSs. The class belongs to the listed grade, so specify it by name on the drawing; an unrated foam of the same PPI does not inherit it.
Send the per-zone numbers, get a quote
Attach the drawing, packing plan, or even a parts photo, with the zone numbers from the checklist. Drawing review typically starts the same business day.
Samples typically 3 to 5 business days; production about two weeks; MOQ varies by material and part. Expedited service available.
Family-owned in Winsted, Connecticut since 1971 · ISO 9001:2015 certified · OEMs worldwide send us a drawing — and get back their part.
Related reading
ApplicationSwitchgear Drawer Slides, Wear Pads & Shipping ProtectionRead →
GuideUHMW, Skived PTFE, or PTFE-Coated Fiberglass: Choosing a Drawout Slide LinerRead →
GuideLow Friction Is Not Low Wear: Specifying Drawout Slide Liners by Contact PressureRead →
IndustryElectromechanical & Switchgear hubRead →
Request a quote for your structural wear & packaging part
Send H-O your drawing or describe the part—engineering reviews every RFQ and converts samples on your geometry.
Last updated · Reviewed by H-O Products engineering (ISO 9001:2015 certified converter, Winsted, CT).
References
- ASTM D1894 (friction methodology); ASTM D3330 (peel); ASTM D3652 (tape thickness); ASTM D882 (thin-film tensile); ASTM D461 (felt methods); ASTM D3575 (polyolefin foams); ASTM D1056 / D1667 (cellular materials); UL 94 (HF-1 classes per listed grade); ASTM G154 (UV exposure, coated filter foams).
- Maker technical data sheets: 6311 UHMW tapes, DW2000 / 6113 PTFE films, 6085 PTFE-glass, SAE felt grades, cork pads, PVC foam range, EPE / EVA / crosslinked-PE densities, Wonder Pads, PolyMask and 4040 films, glass protective film, ePTFE vent membrane, reticulated filter foams.
This checklist supports a quotation workflow; it does not constitute design guidance for any specific assembly. Grade-level values are confirmed on the maker's current technical data sheet; flame classes belong to the listed grades, and assembly-level ratings belong to the tested assembly. All parts are custom manufactured to order; minimum production run quantities vary by material and part. H-O is a die-cut converter, not a raw-material producer.